Over the past five months, over half-a-trillion dollars has flowed into equity funds, according to a report from Bank of America. That’s more than the past 12 years combined, says the financial services company.

There are a number of reasons for the surge in investments. Individual investors have been especially active, as stocks like GameStop and AMC have seen big surges this year, thanks to Reddit’s r/WallStreetBets community. And overall optimism about the pandemic has been on the rise since early November 2020, when Pfizer first reported that trials on its COVID-19 vaccine showed it was 90% effective in preventing first-time infections and it began the process of applying for emergency use authorization from the FDA.

The markets themselves have been helping spur investment enthusiasm as well. The S&P is up 17% in the past five months; the Nasdaq composite index is up 27%; and the Dow Jones industrial average has increased 27% as well.

Approximately $569 billion has gone to global equity funds since November, according to Bank of America’s chief investment strategist Michael Hartnett. In the previous 12 years combined, that total has hit just $452 billion.

That vast investment is raising fears about a pullback, though. All three major market indexes are at or near record highs. Analysts, though, remain optimistic about the markets, and first-quarter earnings, which begin to trickle in next week, are expected to be strong.