Japan Stock Screener
736 companies
Which stocks look cheapest against what their own reports say they are worth? The list is ordered by Intrinsic Value / Market Cap.
Apply suggested sets Return on Investment >= -0.1. Each raised the average return slightly over 2023-2024, on a hold-out half of the companies and on 2025; some single markets and portfolio sizes did worse.
Operating Income ÷ RevenueLatest fiscal yearKeeps profitable businesses. On the current valuation it lowered the Top N return at every threshold tested.
Operating Income ÷ Gross ProfitLatest fiscal yearDrops businesses whose overheads absorb their gross profit. On the current valuation it lowered the Top N return in every mode.
(Cash − Total Debt) ÷ Market Cap × 100Latest quarterAround -50 it drops only the most indebted companies, which helped Traditional Value slightly. Stricter thresholds lowered the return.
(Latest Year Revenue − Prior Year Revenue) ÷ Prior Year RevenueLatest fiscal year vs the year beforeIn Tech, 10% and above kept the cheap companies still growing; the gain was large but not consistent across samples. No effect in Traditional Value.
ΔNOPAT ÷ Growth CapExLatest fiscal year vs the year beforeAt -0.10 or 0 it drops companies whose growth investment lost money, which helped Traditional Value slightly. Higher thresholds lowered the return.
Market Cap ÷ Book ValueLatest quarterAt 10 or below it drops only extreme prices against book value, which helped Tech Value slightly. Tighter thresholds lowered the return outside Tech.
Net income > 0, book value at the start of the latest year, return on equity > 0Latest 3 fiscal yearsLeaves out companies whose 15-year profit projection cannot be made: a loss in one of the latest three years, no book value to measure growth on, or a return on equity at or below zero. Their Profit value is the book value alone, so without this filter the average still includes them on the other two values. On the current valuation it lowered the Top N return in every mode.
NOPAT − (CapEx − Depreciation + Δ Working Capital) > 0, return on capital > 0Latest 3 fiscal yearsLeaves out companies whose 15-year free cash flow projection cannot be made: operating profit or free cash flow at or below zero in one of the latest three years, a change in working capital (from the cash flow statement) above half of operating profit, or a return on capital at or below zero. Technology and Communication Services add half of R&D after tax to NOPAT. Banks are not held to it: their working capital is their loans and deposits. On the current valuation it lowered the Top N return more than any other filter.
Group by Legal Name, keep one row per companyKeeps the newest valuation, then the listing in the company's home country, the USD listing, the country filtered on, the largest market capCollapses the same legal entity listed on multiple exchanges into a single row. For example, Truist Financial appears on the New York Stock Exchange and on two German exchanges; with this on, only the primary US listing is shown. Recommended for portfolio construction; turn off when you need to inspect each individual listing.
Profit value > 3 × the larger of the EPV + Growth and FCFF valuesLatest valuationAfter years of losses, or buybacks larger than the book, the book value is close to zero, so the return on equity and the Profit value explode and the company jumps to the top of the list. Over 36 years of history in 21 countries, leaving these companies out kept the Top N return the same (between −0.2 and +0.3 points a year): it tidies the top of the list, it does not raise the return.
The list
book: the projection was rejected, so the book value stands in its place. K, M, B, T, Q: thousand, million, billion, trillion, quadrillion. A line listed abroad can carry a market cap far below the company's; Home listings only leaves those lines out.
Listed JP, based JP · Technology · Software - Application
Market Cap
$1.63B
Avg Intrinsic
$339.19M
Intrinsic / Market
0.21
Margin of Safety
-379.6%
WACC
10.4%
FY End
2026-05-31
EPV
$545.75M
Profit
$235.91M book
FCFF
$235.91M book
Listed JP, based JP · Technology · Semiconductor Equipment & Materials
Market Cap
$149.04B
Avg Intrinsic
$30.91B
Intrinsic / Market
0.21
Margin of Safety
-382.1%
WACC
11.7%
FY End
2026-03-31
EPV
$25.54B
Profit
$42.81B
FCFF
$24.39B
Listed JP, based JP · Industrials · Specialty Industrial Machinery
Market Cap
$18.32B
Avg Intrinsic
$3.79B
Intrinsic / Market
0.21
Margin of Safety
-384.0%
WACC
8.6%
FY End
2026-03-31
EPV
$2.82B
Profit
$4.27B book
FCFF
$4.27B book
Listed JP, based JP · Technology · Electronic Components
Market Cap
$1.95B
Avg Intrinsic
$390.81M
Intrinsic / Market
0.20
Margin of Safety
-400.1%
WACC
9.3%
FY End
2026-03-31
EPV
$312.35M
Profit
$388.72M
FCFF
$471.35M
Listed JP, based JP · Consumer Cyclical · Footwear & Accessories
Market Cap
$5.46B
Avg Intrinsic
$1.09B
Intrinsic / Market
0.20
Margin of Safety
-401.7%
WACC
8.4%
FY End
2026-03-31
EPV
$606.42M
Profit
$1.48B
FCFF
$1.17B
Listed JP, based JP · Industrials · Aerospace & Defense
Market Cap
$1.21B
Avg Intrinsic
$234.58M
Intrinsic / Market
0.19
Margin of Safety
-416.2%
WACC
10.1%
FY End
2025-12-31
EPV
$234.58M book
Profit
$234.58M book
FCFF
$234.58M book
Listed JP, based JP · Technology · Electronic Components
Market Cap
$3.91B
Avg Intrinsic
$686.09M
Intrinsic / Market
0.18
Margin of Safety
-469.8%
WACC
11.9%
FY End
2026-03-31
EPV
$205.17M
Profit
$952.53M
FCFF
$900.57M book
Listed JP, based JP · Technology · Semiconductor Equipment & Materials
Market Cap
$20.60B
Avg Intrinsic
$3.52B
Intrinsic / Market
0.17
Margin of Safety
-485.8%
WACC
9.7%
FY End
2025-03-31
EPV
$426.75M
Profit
$4.88B
FCFF
$5.25B book
Listed JP, based JP · Technology · Software - Application
Market Cap
$2.12B
Avg Intrinsic
$361.90M
Intrinsic / Market
0.17
Margin of Safety
-485.7%
WACC
10.4%
FY End
2025-11-30
EPV
$361.90M book
Profit
$361.90M book
FCFF
$361.90M book
Listed JP, based JP · Technology · Semiconductor Equipment & Materials
Market Cap
$3.72B
Avg Intrinsic
$624.19M
Intrinsic / Market
0.17
Margin of Safety
-495.5%
WACC
14.1%
FY End
2025-12-31
EPV
$608.30M
Profit
$699.70M
FCFF
$564.55M book
Listed JP, based JP · Consumer Cyclical · Restaurants
Market Cap
$4.60B
Avg Intrinsic
$764.83M
Intrinsic / Market
0.17
Margin of Safety
-501.1%
WACC
9.1%
FY End
2025-12-31
EPV
$81.96M
Profit
$1.01B
FCFF
$1.20B book
Listed JP, based JP · Consumer Cyclical · Apparel Manufacturing
Market Cap
$1.27B
Avg Intrinsic
$205.31M
Intrinsic / Market
0.16
Margin of Safety
-518.5%
WACC
10.5%
FY End
2026-01-31
EPV
$446.39M
Profit
$84.77M book
FCFF
$84.77M book
Listed JP, based JP · Technology · Software - Application
Market Cap
$1.66B
Avg Intrinsic
$262.95M
Intrinsic / Market
0.16
Margin of Safety
-529.6%
WACC
13.3%
FY End
2026-05-31
EPV
$341.63M
Profit
$314.66M
FCFF
$132.56M book
Listed JP, based JP · Technology · Software - Application
Market Cap
$1.26B
Avg Intrinsic
$190.59M
Intrinsic / Market
0.15
Margin of Safety
-558.9%
WACC
10.1%
FY End
2025-12-31
EPV
$247.50M
Profit
$138.16M
FCFF
$186.10M book
Listed JP, based JP · Basic Materials · Chemicals
Market Cap
$20.93B
Avg Intrinsic
$2.95B
Intrinsic / Market
0.14
Margin of Safety
-608.8%
WACC
8.9%
FY End
2025-12-31
EPV
-$1.10B
Profit
$4.98B book
FCFF
$4.98B book
Listed JP, based JP · Consumer Cyclical · Restaurants
Market Cap
$7.35B
Avg Intrinsic
$1.03B
Intrinsic / Market
0.14
Margin of Safety
-615.1%
WACC
6.7%
FY End
2024-09-30
EPV
$990.14M
Profit
$1.36B
FCFF
$736.99M
Listed JP, based JP · Technology · Information Technology Services
Market Cap
$1.00B
Avg Intrinsic
$137.87M
Intrinsic / Market
0.14
Margin of Safety
-628.3%
WACC
10.8%
FY End
2026-03-31
EPV
$189.94M book
Profit
$33.75M
FCFF
$189.94M book
Listed JP, based JP · Consumer Cyclical · Leisure
Market Cap
$2.08B
Avg Intrinsic
$284.17M
Intrinsic / Market
0.14
Margin of Safety
-632.8%
WACC
3.2%
FY End
2026-03-31
EPV
-$146.68M
Profit
$616.21M
FCFF
$382.98M
Listed JP, based JP · Technology · Electronic Components
Market Cap
$8.39B
Avg Intrinsic
$1.11B
Intrinsic / Market
0.13
Margin of Safety
-659.3%
WACC
12.4%
FY End
2026-03-31
EPV
$134.02M
Profit
$1.03B
FCFF
$2.16B book
Listed JP, based JP · Communication Services · Internet Content & Information
Market Cap
$168.98B
Avg Intrinsic
$21.15B
Intrinsic / Market
0.13
Margin of Safety
-699.1%
WACC
10.4%
FY End
2025-03-31
EPV
$25.12B
Profit
$18.33B
FCFF
$19.99B
Listed JP, based JP · Technology · Semiconductors
Market Cap
$130.10B
Avg Intrinsic
$14.35B
Intrinsic / Market
0.11
Margin of Safety
-806.4%
WACC
10.4%
FY End
2026-03-31
EPV
$13.33B
Profit
$14.86B book
FCFF
$14.86B book
Listed JP, based JP · Consumer Cyclical · Restaurants
Market Cap
$2.22B
Avg Intrinsic
$242.20M
Intrinsic / Market
0.11
Margin of Safety
-816.5%
WACC
9.0%
FY End
2026-02-28
EPV
$262.53M
Profit
$316.56M
FCFF
$147.50M
Listed JP, based JP · Financial Services · Asset Management
Market Cap
$1.19B
Avg Intrinsic
$121.28M
Intrinsic / Market
0.10
Margin of Safety
-883.3%
WACC
9.7%
FY End
2025-12-31
EPV
$77.19M
Profit
$219.58M
FCFF
$67.07M book
Listed JP, based JP · Technology · Software - Application
Market Cap
$1.31B
Avg Intrinsic
$128.97M
Intrinsic / Market
0.10
Margin of Safety
-915.2%
WACC
11.1%
FY End
2025-06-30
EPV
$128.97M book
Profit
$128.97M book
FCFF
$128.97M book
Listed JP, based JP · Consumer Defensive · Discount Stores
Market Cap
$2.80B
Avg Intrinsic
$253.94M
Intrinsic / Market
0.09
Margin of Safety
-1003.4%
WACC
6.6%
FY End
2026-06-30
EPV
-$414.10M
Profit
$345.29M
FCFF
$830.64M book
Listed JP, based JP · Industrials · Electrical Equipment & Parts
Market Cap
$19.89B
Avg Intrinsic
$1.73B
Intrinsic / Market
0.09
Margin of Safety
-1051.1%
WACC
10.6%
FY End
2026-03-31
EPV
-$267.57M
Profit
$2.73B book
FCFF
$2.73B book
Listed JP, based JP · Technology · Semiconductor Equipment & Materials
Market Cap
$14.97B
Avg Intrinsic
$1.26B
Intrinsic / Market
0.08
Margin of Safety
-1090.8%
WACC
17.2%
FY End
2026-03-31
EPV
$1.40B
Profit
$1.15B
FCFF
$1.23B
Listed JP, based JP · Industrials · Specialty Industrial Machinery
Market Cap
$3.97B
Avg Intrinsic
$315.91M
Intrinsic / Market
0.08
Margin of Safety
-1156.8%
WACC
10.4%
FY End
2026-03-31
EPV
$201.27M
Profit
$243.00M
FCFF
$503.45M book
Listed JP, based JP · Technology · Electronic Components
Market Cap
$43.43B
Avg Intrinsic
$2.61B
Intrinsic / Market
0.06
Margin of Safety
-1562.8%
WACC
14.2%
FY End
2026-03-31
EPV
$2.48B
Profit
$1.86B
FCFF
$3.49B book
Listed JP, based JP · Industrials · Aerospace & Defense
Market Cap
$1.25B
Avg Intrinsic
$61.80M
Intrinsic / Market
0.05
Margin of Safety
-1926.9%
WACC
10.5%
FY End
2026-01-31
EPV
$61.80M book
Profit
$61.80M book
FCFF
$61.80M book
Listed JP, based JP · Industrials · Aerospace & Defense
Market Cap
$1.08B
Avg Intrinsic
$47.85M
Intrinsic / Market
0.04
Margin of Safety
-2159.8%
WACC
21.5%
FY End
2026-04-30
EPV
$47.85M book
Profit
$47.85M book
FCFF
$47.85M book
Listed JP, based JP · Industrials · Electrical Equipment & Parts
Market Cap
$1.58B
Avg Intrinsic
$45.38M
Intrinsic / Market
0.03
Margin of Safety
-3376.0%
WACC
10.2%
FY End
2025-12-31
EPV
$45.38M book
Profit
$45.38M book
FCFF
$45.38M book
Listed JP, based JP · Healthcare · Biotechnology
Market Cap
$1.12B
Avg Intrinsic
$20.14M
Intrinsic / Market
0.02
Margin of Safety
-5480.9%
WACC
11.6%
FY End
2025-12-31
EPV
$20.14M book
Profit
$20.14M book
FCFF
$20.14M book
Listed JP, based JP · Industrials · Specialty Industrial Machinery
Market Cap
$12.49B
Avg Intrinsic
$118.84M
Intrinsic / Market
0.00950
Margin of Safety
-10413.7%
WACC
6.9%
FY End
2026-03-31
EPV
$118.84M book
Profit
$118.84M book
FCFF
$118.84M book
Listed JP, based JP · Energy · Oil & Gas Equipment & Services
Market Cap
$3.80B
Avg Intrinsic
$24.74M
Intrinsic / Market
0.00650
Margin of Safety
-15261.7%
WACC
7.0%
FY End
2025-12-31
EPV
$17.95M
Profit
$45.89M
FCFF
$10.38M book
Listed JP, based JP · Technology · Electronic Components
Market Cap
$1.25B
Avg Intrinsic
-$46.44M
Intrinsic / Market
-0.04
Margin of Safety
—
WACC
10.4%
FY End
2026-03-31
EPV
-$46.44M book
Profit
-$46.44M book
FCFF
-$46.44M book
| # | Company | Market Cap | Avg Intrinsic | Intrinsic / Market | Margin of Safety | WACC | EPV / Profit / FCFF | FY End |
|---|---|---|---|---|---|---|---|---|
| 701 | 581A.T GO Inc.Listed JP, based JP · Technology · Software - Application | $1.63B | $339.19M | 0.21 | -379.6% | 10.4% | $545.75M $235.91M book $235.91M book | 2026-05-31 |
| 702 | 6857.T Advantest CorporationListed JP, based JP · Technology · Semiconductor Equipment & Materials | $149.04B | $30.91B | 0.21 | -382.1% | 11.7% | $25.54B $42.81B $24.39B | 2026-03-31 |
| 703 | 7013.T IHI CorporationListed JP, based JP · Industrials · Specialty Industrial Machinery | $18.32B | $3.79B | 0.21 | -384.0% | 8.6% | $2.82B $4.27B book $4.27B book | 2026-03-31 |
| 704 | 6834.T SEIKOH GIKEN Co., Ltd.Listed JP, based JP · Technology · Electronic Components | $1.95B | $390.81M | 0.20 | -400.1% | 9.3% | $312.35M $388.72M $471.35M | 2026-03-31 |
| 705 | 8050.T Seiko Group CorporationListed JP, based JP · Consumer Cyclical · Footwear & Accessories | $5.46B | $1.09B | 0.20 | -401.7% | 8.4% | $606.42M $1.48B $1.17B | 2026-03-31 |
| 706 | 290A.T SYNSPECTIVE INCListed JP, based JP · Industrials · Aerospace & Defense | $1.21B | $234.58M | 0.19 | -416.2% | 10.1% | $234.58M book $234.58M book $234.58M book | 2025-12-31 |
| 707 | 6787.T Meiko Electronics Co., Ltd.Listed JP, based JP · Technology · Electronic Components | $3.91B | $686.09M | 0.18 | -469.8% | 11.9% | $205.17M $952.53M $900.57M book | 2026-03-31 |
| 708 | 5016.T JX Advanced Metals CorporationListed JP, based JP · Technology · Semiconductor Equipment & Materials | $20.60B | $3.52B | 0.17 | -485.8% | 9.7% | $426.75M $4.88B $5.25B book | 2025-03-31 |
| 709 | 3994.T Money Forward, Inc.Listed JP, based JP · Technology · Software - Application | $2.12B | $361.90M | 0.17 | -485.7% | 10.4% | $361.90M book $361.90M book $361.90M book | 2025-11-30 |
| 710 | 6871.T Micronics Japan Co., Ltd.Listed JP, based JP · Technology · Semiconductor Equipment & Materials | $3.72B | $624.19M | 0.17 | -495.5% | 14.1% | $608.30M $699.70M $564.55M book | 2025-12-31 |
| 711 | 3197.T Skylark Holdings Co., Ltd.Listed JP, based JP · Consumer Cyclical · Restaurants | $4.60B | $764.83M | 0.17 | -501.1% | 9.1% | $81.96M $1.01B $1.20B book | 2025-12-31 |
| 712 | 456A.T HUMAN MADE INCListed JP, based JP · Consumer Cyclical · Apparel Manufacturing | $1.27B | $205.31M | 0.16 | -518.5% | 10.5% | $446.39M $84.77M book $84.77M book | 2026-01-31 |
| 713 | 4443.T Sansan, Inc.Listed JP, based JP · Technology · Software - Application | $1.66B | $262.95M | 0.16 | -529.6% | 13.3% | $341.63M $314.66M $132.56M book | 2026-05-31 |
| 714 | 2492.T Infomart CorporationListed JP, based JP · Technology · Software - Application | $1.26B | $190.59M | 0.15 | -558.9% | 10.1% | $247.50M $138.16M $186.10M book | 2025-12-31 |
| 715 | 4004.T Resonac Holdings CorporationListed JP, based JP · Basic Materials · Chemicals | $20.93B | $2.95B | 0.14 | -608.8% | 8.9% | -$1.10B $4.98B book $4.98B book | 2025-12-31 |
| 716 | 3563.T Food & Life Companies Ltd.Listed JP, based JP · Consumer Cyclical · Restaurants | $7.35B | $1.03B | 0.14 | -615.1% | 6.7% | $990.14M $1.36B $736.99M | 2024-09-30 |
| 717 | 3778.T SAKURA Internet Inc.Listed JP, based JP · Technology · Information Technology Services | $1.00B | $137.87M | 0.14 | -628.3% | 10.8% | $189.94M book $33.75M $189.94M book | 2026-03-31 |
| 718 | 4680.T Round One CorporationListed JP, based JP · Consumer Cyclical · Leisure | $2.08B | $284.17M | 0.14 | -632.8% | 3.2% | -$146.68M $616.21M $382.98M | 2026-03-31 |
| 719 | 6976.T Taiyo Yuden Co., Ltd.Listed JP, based JP · Technology · Electronic Components | $8.39B | $1.11B | 0.13 | -659.3% | 12.4% | $134.02M $1.03B $2.16B book | 2026-03-31 |
| 720 | 6098.T Recruit Holdings Co., Ltd.Listed JP, based JP · Communication Services · Internet Content & Information | $168.98B | $21.15B | 0.13 | -699.1% | 10.4% | $25.12B $18.33B $19.99B | 2025-03-31 |
| 721 | 285A.T Kioxia Holdings CorporationListed JP, based JP · Technology · Semiconductors | $130.10B | $14.35B | 0.11 | -806.4% | 10.4% | $13.33B $14.86B book $14.86B book | 2026-03-31 |
| 722 | 3387.T create restaurants holdings inc.Listed JP, based JP · Consumer Cyclical · Restaurants | $2.22B | $242.20M | 0.11 | -816.5% | 9.0% | $262.53M $316.56M $147.50M | 2026-02-28 |
| 723 | 319A.T NEXT GENERATION TECHNOLOGY GROUListed JP, based JP · Financial Services · Asset Management | $1.19B | $121.28M | 0.10 | -883.3% | 9.7% | $77.19M $219.58M $67.07M book | 2025-12-31 |
| 724 | 4478.T freee K.K.Listed JP, based JP · Technology · Software - Application | $1.31B | $128.97M | 0.10 | -915.2% | 11.1% | $128.97M book $128.97M book $128.97M book | 2025-06-30 |
| 725 | 141A.T TRIAL Holdings, Inc.Listed JP, based JP · Consumer Defensive · Discount Stores | $2.80B | $253.94M | 0.09 | -1003.4% | 6.6% | -$414.10M $345.29M $830.64M book | 2026-06-30 |
| 726 | 5801.T Furukawa Electric Co., Ltd.Listed JP, based JP · Industrials · Electrical Equipment & Parts | $19.89B | $1.73B | 0.09 | -1051.1% | 10.6% | -$267.57M $2.73B book $2.73B book | 2026-03-31 |
| 727 | 6525.T KOKUSAI ELECTRIC CORPORATIONListed JP, based JP · Technology · Semiconductor Equipment & Materials | $14.97B | $1.26B | 0.08 | -1090.8% | 17.2% | $1.40B $1.15B $1.23B | 2026-03-31 |
| 728 | 6324.T Harmonic Drive Systems Inc.Listed JP, based JP · Industrials · Specialty Industrial Machinery | $3.97B | $315.91M | 0.08 | -1156.8% | 10.4% | $201.27M $243.00M $503.45M book | 2026-03-31 |
| 729 | 4062.T Ibiden Co.,Ltd.Listed JP, based JP · Technology · Electronic Components | $43.43B | $2.61B | 0.06 | -1562.8% | 14.2% | $2.48B $1.86B $3.49B book | 2026-03-31 |
| 730 | 278A.T TERRA DRONE CORPORATIONListed JP, based JP · Industrials · Aerospace & Defense | $1.25B | $61.80M | 0.05 | -1926.9% | 10.5% | $61.80M book $61.80M book $61.80M book | 2026-01-31 |
| 731 | 186A.T ASTROSCALE HOLDINGS INCListed JP, based JP · Industrials · Aerospace & Defense | $1.08B | $47.85M | 0.04 | -2159.8% | 21.5% | $47.85M book $47.85M book $47.85M book | 2026-04-30 |
| 732 | 485A.T POWERX INCListed JP, based JP · Industrials · Electrical Equipment & Parts | $1.58B | $45.38M | 0.03 | -3376.0% | 10.2% | $45.38M book $45.38M book $45.38M book | 2025-12-31 |
| 733 | 4588.T Oncolys BioPharma Inc.Listed JP, based JP · Healthcare · Biotechnology | $1.12B | $20.14M | 0.02 | -5480.9% | 11.6% | $20.14M book $20.14M book $20.14M book | 2025-12-31 |
| 734 | 6594.T Nidec CorporationListed JP, based JP · Industrials · Specialty Industrial Machinery | $12.49B | $118.84M | 0.00950 | -10413.7% | 6.9% | $118.84M book $118.84M book $118.84M book | 2026-03-31 |
| 735 | 6269.T MODEC, Inc.Listed JP, based JP · Energy · Oil & Gas Equipment & Services | $3.80B | $24.74M | 0.00650 | -15261.7% | 7.0% | $17.95M $45.89M $10.38M book | 2025-12-31 |
| 736 | 6740.T Japan Display Inc.Listed JP, based JP · Technology · Electronic Components | $1.25B | -$46.44M | -0.04 | — | 10.4% | -$46.44M book -$46.44M book -$46.44M book | 2026-03-31 |
How to read this page
What Intrinsic Value means
The plain average of three values. Nothing is capped, so it can reach many times the Market Cap.
EPV + Growth
earnings power value plus growth value, less net debt.
Profit
15 years of profit paid to shareholders, plus the book value and the profit kept by then.
FCFF
15 years of free cash flow, plus the capital invested by then, less net debt.
Projections, not exact values. Intrinsic Values are projected from each company's past reports. They show which stocks look cheap compared with the others, not exactly what a stock is worth.
See how this ranking did on past years
The backtest picks the Top N the same way on an older fiscal year and measures what happened to them.
Open the backtest