Backtest · NFLX
Backtest NFLX — Candle by Candle
If you want to find out whether your stop-loss actually protects you, Netflix is the instrument to find out on. It is the clearest gap-risk stock in the catalogue: it has repeatedly opened tens of percent away from the previous close, most famously in April 2022, when it lost around a third of its value between one session's close and the next one's open. No stop placed on the chart helps you there. The order fills where the market opens.
A stop is a price, not a promise
This is the single most under-tested assumption in retail backtesting, and equity data is where it becomes undeniable. On a 24-hour instrument you can half-convince yourself that a stop is roughly honoured. On a regular-hours stock, the market is shut for seventeen and a half hours a day and reopens wherever it likes.
So run the test explicitly. Take your rules through this archive, and every time a position was open across a session boundary, record the fill at the actual opening price rather than at your stop level. The difference between those two equity curves is the cost of overnight risk in your strategy, expressed as a number rather than as a worry.
Then decide, in writing, what your rule does about it: flatten into the close, size down for overnight holds, or accept the exposure knowingly. All three are defensible. Not having decided is not.
What the NFLX data actually is
The archive runs from May 2018 to the most recent session we hold, on every timeframe from one minute to monthly. It is open from the first chart — there is no plan that unlocks more of it, and no shorter window for people who have not paid.
Equity data here is regular hours only — 09:30 to 16:00 New York, no pre-market and no after-hours. That is not a gap in the data, it is what an equity session is, and it has a consequence worth planning for: every trading day opens with a gap rather than continuing from the previous close, so any rule you carried over from an index future or an FX pair is about to meet a discontinuity it has never been tested against.
Prices are split-adjusted throughout, so a chart of 2019 shows what you would compare against today rather than the raw tape. Getting this wrong is the classic silent equity-backtest bug: an unadjusted series prints a 90% single-day crash on the split date, and a stop-loss rule tested through it produces numbers that mean nothing.
How to backtest NFLX without fooling yourself
Mark the earnings dates as you step through them — Netflix reports after the close, so the reaction is always an opening gap, and there are more than thirty of them in this archive.
Model the gap honestly. If your rule would have been stopped out at a level the market gapped through, the trade closed at the open, not at the level. A backtest that assumes otherwise is reporting a drawdown that could not have happened.
The risk of ruin calculator is the right companion here: gap risk is the mechanism by which a strategy with a good win rate still blows up, because it makes the left tail longer than the position size assumed.
Frequently asked questions
Is NFLX backtesting free?
Yes, and there is no card and no trial timer. You get Netflix back to May 2018, with every tool the product has, for 2,000 candles of replay — about two hours of stepping through a chart. After that you top up for $5, or pay $19.99 once and never think about it again. Nothing you buy expires. That window contains the April 2022 session where the stock opened roughly a third lower — the single best gap-risk test available in the catalogue.
How do I backtest gap risk properly?
Fill through the gap, not at your stop. Whenever a position was open across a session boundary and the market opened beyond your stop level, record the exit at the opening price. The gap between that equity curve and the naive one is what overnight exposure actually costs your strategy.
Does the data include after-hours trading?
No — regular session only, which is precisely why this page exists. The move happens while the market is shut, and the chart shows you what a position would really have met: an opening print, not a gentle fill at your level.
Is Netflix representative of the other stocks here?
No, and that is its use. It sits at the extreme of gap behaviour, which makes it the stress test rather than the sample. Prove a rule on a calmer name like <a href="/backtest-aapl">AAPL</a>, then find out here what happens when it meets a discontinuity.
Open NFLX and start stepping
Real Netflix history, split-adjusted, one candle at a time. No account, no card, 2,000 candles free.
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