In what was shaping up to be a low-volume snoozer of a day, things changed dramatically at 10:30am when the DOE confirmed last night's API data according to which US crude inventories had their biggest weekly decline since January even as distillates and gasoline stocks rose. That headline sent WTI soaring by 5.4%, the most since March 16.

The crude spike was all the “momentum ignition” that futures needed to stage a dramatic surge, soaring from 2035, jumping as much as 20 points higher to 2055 before the slightly more hawkish than expected FOMC Minutes reported pushed ES lower by 10 point. And then, out of nowhere, a massive buying program emerged out of nowhere, and sent the E-mini tofresh highs.

It wasn't just oil: an even more notable notable move took place in the biotech sector, which surged by over 5%, its biggest intraday gain since November 2011, and accounted for nearly half of the S&P500's gain. The reason was the collapse of the Valeant-Allergan deal. No really: while talking on CNBC, Brent Saunders said that now that the deal has been pulled, Allergan could weigh deals. That is all the slgos needed to hear and unleashed a massive frontrunning spree, buying up every N/M PE company they could find.

To be sure, as equity algos were scrambling into risk, the VIX was getting crushed, and while it was a last second VIX slam that prevented the S&P from closing red for the year yesterday, today's the selling started early, and from 16 the VIX was back at just around 14 at last check.

Not everyone was rushing into a Risk On mode, however: while the 10Y sold off modestly, it was at 1.75%, back to Monday's levels.

But that didn't stop the S&P500 from closing at the day highs, some 1.1% higher, while the Nasdaq raked in 1.6%, just 80 points away from the “psychological 5000 level” and the highest of 2016, on hope the biotech bubble may be rekindled.