# Long/short ratio and open interest: do crowds predict?

> Do the long/short ratio and open interest predict crypto? 60 scans on 10 Binance perpetuals: 0 of 180 tests survive full correction; the fade lost -66.62%.

Research · Janorium · Published 2026-10-20  
Web page: https://janorium.com/articles/long-short-ratio-open-interest-backtest

Not in a way you could trade. After the crowd was most long, the next days were weaker than usual on 18 of 20 coin-periods — but no test survived a correction over all 180, and the tradable fade, shorting BTC when its long/short ratio hit a 90-day top 10%, lost -66.62%, the same as random shorts. Open-interest surges predicted nothing.

This is the sequel to [funding as a signal](https://janorium.com/articles/funding-rate-signal-backtest). Funding is what a crowded side
pays; Binance also publishes who the crowd is — the share of accounts that are long against those that are short —
and how much leverage is open. The idea traders repeat: when everyone is long, the market goes down to punish them, and
when open interest balloons, a flush is near. Here is what six years of Binance perpetuals say about it.

## Setup

- **Data:** Binance USDT-M perpetuals of ten large coins — BTC, ETH, BNB, XRP, ADA, DOGE, SOL, LINK, LTC and BCH — on
  4h bars. Binance's positioning metrics reach back to 2020-09 for BTC but only to 2021-12 for the other nine, so each
  coin is studied from the first bar its metrics exist to 2026-10-01.
- **The crowd:** Binance's _all-accounts_ long/short ratio (`LSRATIO`, kind `ACCOUNT`) — how many accounts hold a net
  long position for each account holding a net short one. It is the retail-positioning read, not the top-trader one.
  It was above 1 on 79.4% of BTC's bars and on 85.7–100% of each altcoin's, with medians from 1.48 (BTC) to 2.98
  (DOGE): most accounts are long by default, so "crowded" has to be measured against each coin's own range.
- **Three events,** each in the top or bottom 10% of the coin's own readings over the half of the period it falls in:
  the ratio in its top decile (_crowded long_), in its bottom decile (_crowded short_), and open interest — contracts
  outstanding, not their dollar value — growing over 4 days (`OICHG`, 24 bars) in its top decile (_leverage piling
  in_).
- **Statistics:** Research Lab event scans: the mean return 1, 3 and 7 days (6, 18 and 42 bars) after the event against
  the coin's usual return over the same horizon, with a multiple-testing correction (q-value) and a rotation test that
  respects overlapping windows. Each coin's history is split into two halves — up to 2023-09-01 and after — scanned
  separately, so a finding has to show up twice. 10 coins × 2 halves × 3 events = 60 scans, 180 tests.
- **Trading:** two fixed fade rules on BTC, not tuned — short when the crowd is most long, long when it is most short,
  exit after 42 bars (7 days) — at 1x, isolated margin, 95% of the account, 0.05% fee and 0.05% slippage per side,
  funding charged and paid, 2020-09-01 → 2026-10-01.

## The scans: a consistent tilt, not a signal

The 3-day return after each event, minus the coin's usual 3-day return. A tick marks a result that passed its own
scan's correction (q below 0.10):

| Coin | Crowded long, 1st half |     2nd half | Crowded short, 1st half |     2nd half | OI surge, 1st half | 2nd half |
| ---- | ---------------------: | -----------: | ----------------------: | -----------: | -----------------: | -------: |
| BTC  |           -2.25% **✓** |       -0.79% |                   0.00% |       +0.96% |             +0.21% |   -0.31% |
| ETH  |           -2.71% **✓** |       -1.00% |                  +1.14% |       +0.78% |             -0.21% |   -0.69% |
| BNB  |                 -1.55% |       -0.05% |                  +0.27% |       -0.83% |             -0.87% |   -0.25% |
| XRP  |           -3.04% **✓** |       -0.62% |                  -0.63% |       +1.23% |             -0.33% |   +1.82% |
| ADA  |                 -2.46% | -1.93% **✓** |                  -0.07% |       +1.42% |             -1.03% |   -0.23% |
| DOGE |                 -1.89% |       -1.06% |                  +0.89% | +3.32% **✓** |             +2.31% |   +1.71% |
| SOL  |                 -1.94% |       -1.94% |            +5.35% **✓** | +2.13% **✓** |             +1.21% |   +0.16% |
| LINK |                 -2.59% |       +0.35% |                  -2.49% | +3.39% **✓** |             +1.36% |   +0.75% |
| LTC  |                 -1.83% |       +0.25% |                  +0.52% |       -1.34% |             -0.52% |   -0.89% |
| BCH  |                 -0.53% |       -0.62% |                  +1.50% |       -0.86% |             +2.94% |   -0.53% |

**Crowded long** is the one column with a clear direction: the next 3 days were weaker than usual on 18 of 20
coin-halves, by a median of -1.55%, and 18 of 20 were weaker at 1 and at 7 days too. On BTC's first half the effect was
large — -1.84% over 3 days after a crowded-long reading against a usual +0.41%, q 0.017 — and the second half kept the
sign at a third of the size without passing the correction (-0.79%, q 0.149). But the 20 cells are not 20 independent
votes: the coins move together, so their crowded readings cluster in the same weeks. Per scan, 9 of 60 crowded-long tests passed, and
none of them on both halves of the same coin.

**Crowded short** leaned the other way — better than usual on 14 of 20 at 3 days, median +0.89% — with 13 of 60 tests
passing, 9 of them in 2023–2026 and almost all on DOGE, SOL and LINK. It is not stable: LINK's first half passed in the opposite
direction at 7 days (-5.51%) before its second half passed at +7.64%. SOL is the only coin significant in both halves,
and the scan flags its first half's own two halves as disagreeing.

**Open-interest surges** told nothing: better than usual on 9 of 20, worse on 11, and 1 of 60 tests passed. Read as
numbers rather than events, neither the ratio nor the change in open interest predicted the next 1, 3 or 7 days in any
of 120 tests.

Now the count that matters. 23 of the 180 tests passed the correction inside their own scan, where it covers only that
scan's three horizons. Correct over all 180 together — the questions were asked of the same market, and that is how
many were asked — and **none** passes: the strongest, LINK's crowded short in 2023–2026, has a p-value of 0.002 and a
corrected q of 0.26.

## Trading the fade

A trader cannot know in 2021 where the top decile of 2020–2023 will be, so the trading rules compare the ratio only
with its own last 90 days (a trailing percentile rank over 540 bars). On BTC:

**Backtest: [Long/short ratio fade: short when the crowd is most long (90-day top 10%), hold 7 days](https://janorium.com/backtests/795)**  
BTCUSDT · 4h · Futures · 2020-09-01 → 2026-10-01

| Return | Max drawdown | Sharpe | Win rate | Trades |
| --- | --- | --- | --- | --- |
| -66.62% | 72.80% | -0.35 | 47.3% | 110 |

*Short BTC when the long/short ratio is in its 90-day top 10%, hold 7 days — -66.62%*

**Backtest: [Long/short ratio fade: long when the crowd is most short (90-day bottom 10%), hold 7 days](https://janorium.com/backtests/796)**  
BTCUSDT · 4h · Futures · 2020-09-01 → 2026-10-01

| Return | Max drawdown | Sharpe | Win rate | Trades |
| --- | --- | --- | --- | --- |
| +103.56% | 53.58% | 0.53 | 53.0% | 100 |

*Long BTC when the long/short ratio is in its 90-day bottom 10%, hold 7 days — +103.56%*

Shorting the crowded long lost -66.62% over 110 trades, even with 1,705.39 USDT of funding received along the way. It
lost in both halves. To see whether that is bad luck or no information, 2,000 sets of 110 random 7-day BTC shorts were
simulated over the same window, with the same costs and funding: their median was -69.06%, and the rule landed at the
55th percentile — indistinguishable from shorting at random.

The scans and the backtest disagree because they ask different questions. The scan's "top 10%" is drawn over the whole
half with hindsight. A dry run of the short with that hindsight threshold made +81.35% on BTC in 2020-09 → 2023-09 —
and -7.32% in 2023-09 → 2026-10 with the second half's own hindsight threshold. The trailing version, the only one
you could have traded, lost in both.

Buying the crowded short made +103.56% over 100 trades, after paying 2,284.53 USDT of funding. Against 2,000 sets of
100 random 7-day longs (median +5.81%) it sits at the 85th percentile — better than most, not unusual — and holding BTC
over the same window made +615.67%.

> **What this test does not show**
>
> - **One crowd measure.** The all-accounts ratio counts accounts, not money. Binance's top-trader ratios (by position
>   size or by top accounts) start later and could behave differently.
> - **Hindsight in the scans.** The event thresholds are deciles of each half's own readings; that is fine for describing
>   what happened and useless for trading, as the dry runs show.
> - **Short history.** Nine of the ten coins have metrics only from 2021-12, so their first half is 21 months of mostly
>   bear market.
> - **One exchange.** Positioning on other venues and in aggregate data can differ from Binance's.

## Conclusion

- A crowded long book on Binance was followed by slightly weaker days on almost every large coin, 2020–2026, but no
  single result survived a correction over the 180 tests asked, and none repeated on both halves of a coin.
- The fade you could actually trade — short BTC when the ratio hits its 90-day top 10% — lost -66.62%, no better than
  random shorts; buying the crowded short made +103.56% against +615.67% for holding.
- Open-interest surges predicted nothing, as events or as numbers.

The method is the one from [funding as a signal](https://janorium.com/articles/funding-rate-signal-backtest); the metrics are explained in
[the backtest metrics guide](https://janorium.com/guides/backtest-metrics-explained).