ETH 2500 Put OI Rose 151 Contracts — the Tape Says a Whale Sold Them
ETH's 2500 put (Sep 25 2026 expiry) shows a textbook OI-vs-tape mismatch. Over 24h, put OI at the strike rose 151 contracts while call OI at the same strike unwound by 501 — a combined read that could pass for defensive put accumulation. The taker tape disagrees: aggregate flow at 2500 shows buyerAggression of just 0.14, net premium -$45,151, across 3 block trades and 24h volume of $62,809.
Zooming into the 48h aggressor timeline confirms who was pressing:
| Bucket (UTC, Sep 3) | Dominant side | Net premium (USD) | Block trades |
|---|---|---|---|
| 02:00-03:00 | buyer | +21,648 | 0 |
| 14:00-15:00 | buyer | +10,558 | 0 |
| 15:00-16:00 | seller | -128,091 | 1 (-$2.49M notional) |
| 16:00-17:00 | seller | -5,424 | 0 |
The 15:00 bucket alone flipped the whole window: a single block trade sold 1,073 contracts ($2.49M notional) of the 2500 put, dwarfing the modest buyer-led flow seen earlier that day. Total 48h sell premium ($145,157) outweighs buy premium ($60,316) by 2.4x. Rising put OI here reflects a writer opening short puts and collecting premium, not a buyer stacking downside protection.