In a research note on Tuesday, Bank of America analysts said clients of BofA Securities were net buyers of U.S. equities for the first time in three weeks.

The $6.1 billion net inflow in the prior week marked the fifth largest in BofA’s records. Clients bought both single stocks and exchange-traded funds, but analysts pointed out that the single-stock inflows were the largest in BofA’s data history, which goes back to 2008.

The note also said all major client groups—including retail investors, hedge funds, and institutional investors—were net buyers. Clients bought stocks in all sectors except energy, led by technology and discretionary shares, which also saw the biggest weekly inflow on record.

And that was before the stock market set fresh record highs over the past week as new inflation data gave the Federal Reserve more leeway to cut rates in the near future and Fed Chairman Jerome Powell sounded increasingly dovish.

The surge of interest in single stocks comes as stock-picking has been overshadowed by passive investing in recent years, with funds that track indexes like the S&P 500 drawing more and more capital while actively managed funds continue to underperform the market.

But the AI boom has highlighted a handful of tech giants with astronomical gains, which are driving the bulk of the market’s recent advances. In fact, Nvidia alone accounted for more than a third of the S&P 500’s year-to-gains as of June.

Such stock market concentration means it’s harder than ever to find stocks that are beating the overall market, underscoring the outsized role that certain individual stocks are playing.

The percentage of S&P 500 stocks that are outperforming the index has fallen to a record low, diving below 25%, according to Apollo Global Management chief economist Torsten Sløk, who quipped in a note Thursday that “stock picking in the S&P 500 essentially boils down to whether you like tech or not.”