you can trade bitcoin for cash balances at various exchanges but actually withdrawing those balances is subject to miniscule daily/monthly withdrawal limits and if there's a run on the market those exchanges will almost certainly collapse. there's no significant over the counter market. you can swap your bitcoin or tether for other crypto currencies but none of those have independent exchanges/markets. the best you can probably do with them is trade them back for bitcoin.
if you're a market participant who thinks things are a scam your best option is to withdraw what you can while you can and do everything you can to prop up the price until you are liquidated