As Bloomberg notes, at 11:21am ET on Thursday, a trader sold close to 4 million shares worth $322 million of the HYG High Yield Bond ETF.

About five minutes later, 8 million shares worth $267 million of the JNK High Yield Junk Bond ETF were also sold. Then, another $350 million worth of HYG was unloaded at 1:39 p.m.

Commenting on the liquidations, Josh Lukeman, head of ETF market making at Credit Suisse noted - with a fair dose of snark - that after a relentless rally into high yield as recently as the end of September, junk bonds are no longer "a popular place to park cash." In fact, investors can't wait to get out as BWIC suddenly emerge: