ETH's Sep-25 2500 Call Tops OI Growth, But the Buyer Spent Barely $2k

The Sep-25 2500 call (spot $1,709.49, ~46% OTM) is the single largest OI mover across its entire expiry chain over the last 24 hours. Taker flow was overwhelmingly buyer-led — 93.6% buyer aggression on the 24h flow signal, and the wider 7-day aggressor tape shows buyer-dominant hourly buckets almost throughout, with $3,967 total buy premium against $2,112 sold.

Strike	Call OI Δ (24h)	Put OI Δ (24h)	Net signed flow
2500	+13,788	0	+13,788
1600	+703	+423	+280
1800	+182	0	+182
1900	+162	0	+162
2000	-181	0	-181

Raw OI delta alone reads like an aggressive institutional build. The premium tape says otherwise: total dollar flow on this strike over 24h was roughly $1,700, and zero block trades touched it. Compare that to same-expiry strikes where blocks did the work — 1900 put sold $567.5k in premium, 3400 put $778k, both via single block prints. The 2500 call's OI headline is loud; its dollar footprint is quiet, cheap optionality bought in size rather than size bought expensively.