The daily average on Friday was 0.19. We'll see today. But 5/16 isn't THAT far off it and it's only slightly over the 4/16 target top end.
Your theories would be that either:
1) JPM is viewed as a counterparty risk by other funds market participants; 2) The Fed is draining reserves from the system gradually by edging towards the 0.25% (supported by data), and JPM was caught short; 3) There was a bank run on Chase. 4) ????