Fractional shares
Buying part of a share, so $5 can buy any stock.
Fractional shares let you buy a slice of a share instead of a whole one. If a share costs $500, $50 buys you a tenth of it.
Why it matters for DCA
Without fractions, a $50 monthly plan could not buy a $500 stock at all, and part of every buy would sit unused as cash. With fractions, every dollar gets invested on schedule.
What to check
Not every broker offers fractional shares for every stock or ETF, and some limit them to market orders. Check before you set up a recurring plan.