{"id":"evt_1111111111111111111111","type":"position_increased","wallet":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","asset":"BTC","side_before":"long","side_after":"long","notional_before_usd":7800000,"notional_after_usd":35100000,"notional_delta_usd":27300000,"position_change_notional_usd":27300000,"exposure_change_pct":3.5,"withdrawable_before_usd":null,"withdrawable_after_usd":null,"withdrawable_delta_usd":null,"observed_asset_rank_before":12,"observed_asset_rank_after":5,"observed_asset_share_before_pct":1.2,"observed_asset_share_after_pct":5.51,"participant_context_label":"#5 observed BTC participant","attention_label":"Major participant change","attention_reason":"Top-10 observed BTC participant increased exposure by $27.3M","attention_tier":2,"observed_from":"2026-08-27T02:12:00Z","observed_to":"2026-08-27T04:12:00Z","sampling_frame":"deep","coverage_before":0.311,"coverage_after":0.333}