One trader who has been betting against the crowd on a market blowup was able to make hundreds of millions of dollars amid last week's wild market volatility, according to Macro Risk Advisors.

The Cboe Volatility Index, or VIX, is a key measure of market expectations of near-term volatility conveyed by S&P 500 stock index option prices. It's sometimes called the "fear gauge."

The VIX surged by 115.6 percent last Monday to 37.32. It rose briefly early Tuesday to over 50, the highest level since August 2015. The measure spent most of the second half of 2017 at or below 10 as hedge funds continued to bet successfully on smooth sailing for the stock market ... until last week. That's when the losing bet for this trader paid off.

"At one point, he was down $200 million, most of that permanently lost in expired option premium. At one point, '50 Cent' became '30 Cent,' scrimping on his usual VIX option purchases, unwilling to pay up for the 50 cent VIX options that were his namesake," Pravit Chintawongvanich, head of derivatives strategy at Macro Risk Advisors, wrote in a note to clients Monday. "But in early February, when it seemed like Fiddy's fortunes could go no lower, it came: redemption."