CNBC host Jim Cramer has long made wild predictions on his program, Mad Money, and viewers and investors alike often respond with mild agreement or disagreement. In the case of his Thursday show, Cramer raised an issue with which many investors and experts are taking exception. Cramer called Cathie Wood’s Ark Investment Management ($ARKK@US) the ultimate hedge fund, and he even noted that there’s an ETF that bets against Wood, known as the Tuttle Capital Short Innovation ETF. Even so, Ark’s YTD returns are down 30%, and Cramer made mention of a “drowning” sequence that has elicited eye-rolls from experts. Cramer went on to say that Wood should close her funds to new investors as if taking on new investors will hamper long-term performance. Viewers should keep in mind that Cramer has reversed course on other investments in the past, garnering quite a lot of publicity because he’s on TV every day. For Wood’s part, she said that you cannot simply close an ETF and she believes that Cramer was referring to mutual funds. At press time, the ARK Innovation ETF was trading at $66.33, down almost 4%.