Longtime investor Bill Gross believes Elon Musk’s Tesla is behaving like a speculative play among retail investors.

“Tesla acting like a meme stock — sagging fundamentals, straight up price action,” the former chief investment officer and co-founder of Pimco said in a post Tuesday afternoon on X. “But then there seems to be a new meme stock every other day now. Most are pump and dump.”

Tesla is on a stunning 10-day winning streak, up a whopping 43.6% since June 24. The rally was initially triggered by Tesla’s second-quarter vehicle production and deliveries numbers that beat analyst expectations.

Gross, who at one time was the most influential investor in the U.S. bond market, seems to think that the strong delivery report wasn’t enough to justify such an eye-popping run.

The 80-year-old investor also compared Tesla with Chewy, Zapp and the “old favorite” GameStop. Chewy recently gained meme status after online personality Roaring Kitty, who inspired 2021′s GameStop mania, bought a sizable stake in the pet retailer.

Gross revealed previously that he dabbled in trading GameStop and AMC options for quick profits in 2022, calling those “lottery ticket stocks.”

Shares of Tesla are still up just about 6% year to date, lagging the S&P 500, which has gained 17%.