Already ensconced in controversy and veiled in complexity, volatility ETNs  arguably suffered a major blow today as the VelocityShares Daily 2x VIX Short-Term ETN (NYSE:  TVIX  ) has become the story du jour for plunging over 25%. Volume in  TVIX has reached more than double the daily average and there's still time left in the trading day.

While  TVIX isn't an exchange-traded product most investors are familiar with, the ETN's lack of popularity prior to today belies its size. Simply put,  TVIX was not a small ETN at the start of today. In fact, it had over $500 million in AUM. That's almost the same size as the Market Vectors Indonesia ETF (NYSE:  IDX).

What folks are having a hard time understanding is how is  TVIX getting taken to the woodshed while ETNs such as the iPath S&P 500 VIX Short-Term Futures ETN (NYSE:  VXX) and the iPath S&P 500 VIX Mid-Term Futures ETN (NYSE:  VXZ) are trading higher. To be frank, all three have some of the ugliest charts around.

As we noted earlier today,  TVIX 's bubble bursting has a lot to do with the fund trading at rich premium to its net asset value, a situation brought about by Credit Suisse (NYSE:  CS)  halting the creation of new  TVIX shares last month.

Speaking of Credit Suisse, it's may not be coincidence that its U.S.-listed shares are trading down almost 2.4% as  TVIX plunges. ETN's are bond instruments, not funds, and though ETNs pay no interest the way a corporate bond or a U.S. Treasury does, by purchasing shares of  TVIX , one becomes an UNSECURED CREDITOR of Credit Suisse. Translation: ALL ETNs have the potential to expose traders and investors to credit risk.

Last month,  FT Alphaville broached the subject of  TVIX buyers running into the ETN with Credit Suisse's creation limit in mind. So it's not that far flung that punishing  TVIX could be a method of backdoor shorting Credit Suisse. At the very least, beating up  TVIXtoday has proven to be a small pain for Credit Suisse's ADRs.

Along those lines, it would not be stunning to see Barclays (NYSE:  BCS) trade lower if VXZ ever experiences a day like  TVIX has today. Barclays is the parent company of iPath. Buy VXZ or VXX and you become a Barclays creditor.

Oh yeah, that sigh of relief heard across the ETF universe today came courtesy of ProShares and Direxion. The two largest U.S. issuers of inverse and leveraged ETFs are probably quite happy there's a new exchange-traded products whipping boy and it's  TVIX , not the Direxion Daily Financial Bear 3X Shares (NYSE:  FAZ) or a similar fund.