Most every broker is going to advise you to remain fully invested or close to it.
Brokers have two goals: bring assets in and retain those assets.
Going to cash, makes it easier for people to take money out, transfer out, etc. So they discourage that. Also, a ton of brokers have no idea when the market, fund or stock gets super risky. But in the end, that decision has to be yours.
A money market fund is ideal. It’s like a souped up savings account. It just earns slightly more interest on your cash while you await the stock sell-off.