Gold Withheld is a side effect of the regulatory safeguards that are in place to protect users, brokerages, and the market. You could have Gold Buying Power withheld for a few reasons:
Your portfolio value drops below your selected tier.
Robinhood can only extend up to double your portfolio value in Gold Buying Power. If your portfolio value drops below your tier, some of your Gold Buying Power will be withheld until your portfolio value goes back up.
You’re investing in high-volatility stocks.
Robinhood can only extend a certain amount of Gold Buying Power for each stock. You’ll get more buying power for low-volatility stocks than medium- or high-volatility stocks. Any Gold Buying Power unavailable for medium or high-volatility stocks will be withheld.
High-volatility stocks will decrease the amount of day trade buying power that you’re issued at the start of the day.
You may also encounter restrictions when you try to sell high-volatility stocks. This is to prevent you from placing a day trade that would cause you to exceed your day trade buying power limit. Placing a day trade that will cause you to exceed your day trade buying power will result in a violation and may require you to make an additional deposit to keep trading.