What kind of account do you keep your cash in?

I keep my cash in my TD Ameritrade account (have an automated monthly transfer). I've been hoarding my profits, dividends, & transfers as cash, since the summer & intend to start buying again (high yielding dividend & a few to DCA down) over the next several months (longer?) What do you do with your cash, to enable you to spend during dips? I'm not interested in savings accounts or accounts that don't let you withdraw large amounts within 2-3 month intervals.