BTC 79000 Call OI Jumps 122% While the Tape Shows Sellers, Not Buyers
BTC's 79000 call (2026-09-25 expiry, ~23 DTE) added 1,254.6 contracts of open interest in 24 hours -- 1,024.9 to 2,279.5, a 122% jump worth roughly $99.1M notional. Read in isolation, that looks like fresh directional call buying stacking up above spot.
The aggressor tape tells a different story for the exact hours the OI built (00:00-12:00 UTC Sep 2):
| Bucket start (UTC) | Buy prem $ | Sell prem $ | Buyer aggression | Block net $ |
|---|---|---|---|---|
| 00:00 | 69,119 | 901,989 | 0.07 | -34.7M |
| 04:00 | 18,149 | 635,647 | 0.03 | -23.3M |
| 08:00 | 19,321 | 663,573 | 0.03 | -30.6M |
Over the full 48h window the strike's net premium flow is -$1.865M (buy $456.7k vs sell $2.32M), overwhelmingly seller-led even as OI exploded higher. Across the whole Sep-25 expiry, call OI added 3,694.7 contracts versus 464.1 on puts -- but the 79000 strike alone accounts for a third of that call build, almost entirely during hours when takers were net sellers of premium via block trades.
OI growth and aggressive buying are not the same signal here. The size and timing point to dealer-side inventory transfer rather than organic directional demand chasing 79000 calls.