A cross-venue, long-short event trade. The signal is the gap between the price of the same coin's USDT perpetual on Bybit and on Binance USD-M. We do not trade that gap (it is only a few basis points, sd 3-14 bp, far below a two-leg round trip). We read it as a crowding gauge. Bybit's flow skews toward retail and high-leverage traders. When Bybit's perp stays rich to Binance's for a full day, aggressive one-sided demand on Bybit is pushing price faster than arbitrageurs move it back. That positioning tends to unwind, and the coin underperforms over the next half-day. A persistent Bybit discount is the mirror case. The position is a single leg on the BYBIT perp of that coin; Binance USD-M bars are a signal source only. Universe, fixed in advance at 7 names, below the ~10-name cap of L173: SOL, XRP, DOGE, LINK, ADA, AVAX, LTC. BTC and ETH are excluded because the Bybit-Binance basis on the two largest books is arbitraged by large desks and is pure noise (ETH premium sd 2.6 bp). DISCLOSURE: ETH was in the pre-study and showed the opposite sign (-0.37%/trade, n=109), so this exclusion is partly ex-post. Data: 4-HOUR bars from the catalog for <COIN>USDT.BYBIT (Bybit linear perp collector, gap-free from 2020-10 to 2021-10 depending on coin, through 2026-09-30) and <COIN>USDT.BINANCE (Binance Vision klines, 0-2 single-bar gaps). Both were checked in the catalog on 2026-10-01. No supplementary feeds are needed. Point-in-time pre-study (4H closes; enter at the next bar; z = 6-bar mean of premium_bp minus its 180-bar mean, divided by the 180-bar sd; |z|>1.5; 12h clock; non-overlapping) gave these mean contrarian returns per trade: SOL +1.21% (n=77), ADA +1.92% (47), LINK +0.43% (60), LTC +0.39% (36), AVAX +0.27% (33), XRP +0.17% (43), DOGE +0.02% (68). The pooled mean is about +0.66% on 364 trades, against a 0.11% Bybit round trip. The effect is concentrated in SOL and ADA. Pooled t is about 2, which is modest, and the predictions below are set accordingly. This is a new economic claim: venue-composition crowding read off a cross-exchange price gap. It is not a funding, OI or taker gate on a trend trade (L111). It is not a convergence arb (the gap itself is not traded). It is not a symbol swap of the TSMOM survivor (L112). It also adds to the BYBIT (2.2%), cross-venue (7.2%) and long-short (15.6%) buckets, all of which are under quota.