For most intents and purposes, SVXY has the same characteristics as XIV. As rough "proof" of this, have a look at a 6-month or longer chart of SVXY:XIV. Prior to this week, it was a very flat line at about 0.95. .
Ophir Gottlieb wrote an interesting article about what really happened to XIV. "It's a reminder that the real danger to a portfolio is not a bear market -- we recover from those quite nicely as a nation -- it's the delirium that happens when a bull market gets totally out of control and margin is used excessively in a spurt of just a few days. And by margin, we don't mean normal, everyday investors, we mean the institutions -- even the ones we entrust to be custodians of our investments. So that's it. XIV likely would have done just fine after this moment in time in the market, will not be given that opportunity to recover. It has been blown out on the heels of yet another Wall Street debacle, which no one seems to even understand, yet." The problem, as usual, is not the instrument - it's how you use it. Leverage is what is killing accounts. The Astonishing Story Behind XIV Debacle To learn from history: The Lessons From The XIV Collapse