It is taken for granted in some circles that FTX sold bitcoin and eth as soon as they were deposited to prop up FTX backed tokens, like FTT or Solana.
“FTX and Alameda sold down the crypto markets with our assets to fund their unprofitable gambling. Markets would otherwise be much higher,” Andrew Kang of Mechanism Capital said back in November.
Source: https://www.trustnodes.com/2023/04/12/did-ftx-sell-one-million-eth