This sounds like something I should have known 15 years ago, but alas I admit I don't... I've always had a 401k before - on a 401k I would contribute every 2 weeks, and it would buy fractional share at each contribution time - without a per-share fee. So you get a really nice DCA up throughout the year. How do you do that in an IRA account? You're effectively limited to $105 per week. If I buy let's say 1 share of TSLA every 2 weeks however, I'm going to be increasing my share price by $10 each due to brokerage fees. I can of course do purchases only once per year, but then it's not really DCA, and you need to actually worry about timing. Is this just an effect of my brokerage (TD Ameritrade) and I need to find a more IRA friendly broker that do fractional shares at a lower cost? Or are all IRA accounts like that?