Buying of shares by company insiders surged in May, but retail investors may want to hold out a little longer before following their lead. According to data from The Washington Service, through May 23, the insider sales value ratio was at its highest monthly level since March 2020. The number of inside buyers has reached 1,200, this is the biggest month of the year so far and is tracking more sellers for the first time in more than two years. Buyers include CEOs of major companies, such as Uber boss Dara Khosrowshahi, who bought $5.3 million worth of stock on May 6, according to VerityData/InsiderScore.com. Some of the recent purchases have come from stocks that have fallen more than 25% for the year. Insider buying is often seen as a positive sign by professional investors. Acquisitions by executives and board members could be a signal that insiders are optimistic about the company’s prospects. Historically, an increase in insider buying during a market downturn tends to occur near the bottom of a pullback. For example, the strong buying in March 2020 coincided with the market finding a bottom and breaking out again, as the Federal Reserve stepped in to support financial markets. Insider buying also spiked in January 2019, shortly after the sharp sell-off on Christmas Eve, according to Washington Service data. Still, investors should be wary of seeing gains this month as executives call the bottom of a market sell-off, said Ben Silverman, research director at VerityData. While buying was strong, it wasn’t overwhelming. “All those periods, insiders were doing really, really sharp market bottom calls and that was evident by the historical buying volume at the time. Even though the numbers are now The currents look good, but they’re still low compared to those times,” Silverman said. Also, this month’s spike in purchases could be helped by earnings season. Once the companies reported the results, their insiders were allowed to trade more freely. For the first quarter, that impact is typically stronger in the first half of May, according to research by VerityData, as the month goes by, purchasing activity has dwindled, Silverman said. “We’d really like to see buying pick up, and then sustain for a few weeks. And instead, we’d see buying pick up again,” Silverman said. Still, Silverman said he’s “optimistic” that buying levels suggest some stocks are undervalued. Insider buying was particularly strong among Russell 2000 companies, he added. Here are a few companies that have seen top executives buy shares in the past month, according to VerityData: Paramount Global Starbucks General Motors General Electric Carnival Corp.