Investors in exchange-traded funds are brushing off billionaire Warren Buffett’s dire warnings on the airline industry.

The US$580 million U.S. Global Jets ETF, ticker JETS, has seen 44 straight days of inflows totaling US$632 million. The cash streak extended even after Buffett said Berkshire Hathaway Inc. has completely exited its positions in airlines, cautioning that the prospects have changed as a result of the coronavirus outbreak.

Traders eager to capture a rebound in airline stocks are driving flows into JETS, according to WallachBeth Capital’s Mohit Bajaj. Buffett abandoned his bet on the four major U.S. airlines, which are the ETF’s top holdings. However, the ETF has 34 positions in total, spreading the risk, Bajaj said.

“The sector has already sold off pretty dramatically,” according to Bajaj, WallachBeth’s director of ETFs. “By buying the ETF, it mitigates the risk from owning any single airline company.”

Buffett’s grim outlook for the industry did little to deter individual investors, who have piled into the ETF. The number of users at retail trading platform Robinhood who are holding JETS surged to more than 19,000 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.

JETS fell 1.2 per cent at 2:02 p.m. in New York after initially rallying. The ETF has dropped nearly 58 per cent so far in 2020, with the bulk of losses coming after mid-February once lockdown measures took effect around the globe in an effort to contain the spread of infections.

Demand to bet against the beleaguered fund remains muted despite its tumble. Short interest as a percentage of shares outstanding on JETS -- a rough indicator of bearish bets on the fund -- is currently 2.2 per cent, according to data from IHS Markit Ltd. It reached 7.8 per cent in February 2019.

To Chris Zaccarelli at Independent Advisor Alliance, any bottom-calling wagers on airlines are premature given that the impact of the coronavirus has the potential to dampen air travel demand for several years. Additionally, people will likely be unwilling to fly until there’s a vaccine and airlines will have to contend with the costs of flying planes with empty seats until then, he said.

“Demand has been crushed and the stock prices have reflected that, which is why many people think this is a good entry point,” said Zaccarelli, chief investment officer at the firm. “What’s being missed is that future demand is going to be adversely affected for at least another year, and possibly for years to come.”