When deciding how much stock to buy at once, the "right" amount is usually determined by two main factors: your total portfolio size and your preferred entry strategy. Core Rules for Position Sizing
There are two common ways to actually pull the trigger on a purchase: how much stock should i buy at a time
Dollar-Cost Averaging vs Lump Sum Investing | Morgan Stanley When deciding how much stock to buy at
: If you are using a broker that charges commissions, try to invest at least $1,000 per trade. This keeps transaction fees from eating more than 1%–2% of your purchase price. : Limit any individual stock to roughly 5%–10%
: Limit any individual stock to roughly 5%–10% of your total portfolio. This "position size" ensures that if one company fails, it won't wipe out your entire savings.
Experts generally suggest that you should not let a single stock dominate your holdings.