An E*Trade Financial survey found that roughly three-quarters of retail investors believe the market is “fully or somewhat” in a bubble, a 3 percentage-point increase from the previous quarterly poll. At the same time, bullish sentiment has increased, rising to pre-pandemic levels at 61%.

“Optimism grew as the market hit new all-time highs, vaccines increased, stimulus measures continued, and earnings estimates are high,” said Mike Loewengart, managing director of investment strategy at the firm.

Stocks have been on a tear for more than a year, and bubble warnings have rung out during most of that time. But the latest leg up has stretched valuations to levels last seen in the dot-com era, and with yields surging, the chorus has grown so loud retail investors have taken note. But most ignore it — just as they’ve done as the S&P 500 surged 83% from the pandemic lows — betting that there’s money to be made as long as the government’s spending and the Federal Reserve is keeping policy loose.

They’ve consistently bought when the pros shied away and made early bets on stocks that will benefit most from a return to normal economic activity. For the last 12 months, they’ve plowed an average of $1.2 billion into stocks daily, according to data from VandaTrack.

In some circles, the relentless buying by individual investors is stoking concern that the group is poised to pull back, creating a risk to the broader market. The equity allocation of U.S. households probably rose to 40% in April, surpassing the dot-com peak and reaching the highest level since the early 1950s, according to an estimate from JPMorgan Chase & Co.

At various times over the past year, the retail frenzy has spurred concerns from professional investors who warned that their involvement, similarly to the early 2000s, signified too much euphoria. But they’ve not shied away yet. At Bank of America Corp., individuals were net buyers of stocks for a sixth straight week, according to the firm’s latest data on client funds. That contrasts with professional investors who took advantage of recent gains to offload holdings.

E*Trade polled nearly 1,000 retail investors who manage at least $10,000 in their online brokerage accounts. The survey also showed nearly half believe the economy is in better shape, a 15 percentage-point increase versus the prior quarter’s results. And though concerns around virus-related risks dropped amid the recent vaccine rollout, market volatility concerns increased and now rank as the top risk to investor portfolios, according to the survey.

Whether or not retail investors continue to play a big role in markets will depend on what happens when there’s a meaningful pullback, according to Max Gokhman, head of asset allocation at Pacific Life Fund Advisors.

“What happens when there’s no new fuel for this rocket ship to the moon? A lot of the diamond-hands crowd may realize they’ve been overpaying for shoddy cubic zirconia,” he said, referring to a popular phrase describing bullish gumption. “Whether they stay in the markets after that will determine the long-term effect of retail.”