Let’s say you plan to buy a house in 12-18 months. You have the money for a down payment, but it’s in the market right now (combo of ETFs and individual stocks). 

Do you:
(1) Keep the money in the market but in a more conservative portfolio 
(2) Put the money in a savings account and sit on it
(3) Something else

Good question. Numbers matter so hard to give a definitive answer. 

Yields are likely to come down, which means stock may go up. Though when you sell equities you will pay capital gains tax which will hurt you. 

I’d recommend, don’t sell but shift your savings towards cash somewhat. Get to your target in savings or close and cash out equity if you need.