This week’s stock turmoil has finally ended the relentless inflows into a once-niche ETF investing in airlines.

The U.S. Global Jets exchange-traded fund, ticker JETS, posted a US$14 million outflow as the shares of major carriers convulsed in recent days.

That ended 70 consecutive days of inflows which had boosted assets in the fund to US$1.4 billion from as little as US$33 million in March, according to data compiled by Bloomberg.

JETS, whose top holdings are the four main U.S. airlines, emerged as a popular vehicle for “bored” retail traders to bet on a rebound in the sector in the past few months. However, growing fears surrounding a potential second wave of the coronavirus have roiled the market -- and battered carrier shares anew.

“With the looming concern that COVID rates might start to increase, this will continue to affect the airline and travel industry,” said Mohit Bajaj, WallachBeth Capital’s director of ETFs. “A lot of the selling yesterday was driven by the retail space unwinding positions.”

JETS remains down over 40 per cent this year, a plunge that has enticed scores of retail traders eager to catch the bottom. The number of users holding JETS on trading platform Robinhood surged to roughly 37,000 this week, according to Robintrack, a website unaffiliated with the site that uses its data to show trends in positioning. That compares to 500 at the beginning of March.

Meanwhile, demand to wager against JETS remains muted. Short interest as a percentage of shares outstanding -- a rough indicator of bearish bets on the fund -- is currently 1.5 per cent, according to data from IHS Markit Ltd. That’s roughly in line with the five-year average and a far cry from the almost 8 per cent reached in February 2019.