How many shares should you buy ( great question Lee) ? The minimum you can purchase is one share. You can buy fractional shares with your dividends in certain types of brokerage accounts. Our purposes we are always talking 1 share. Stock is traditionally traded (bought and sold) in 100 share blocks. Any thing less, say 53, 94, or 5 is considered an "Odd Lot", and an Odd Lot" trade. Here's how it works: You buy 1 share of Stock at $5.00 + $1.00 commission = $6.00 cost but $5.00 value You buy 10 shares of Stock at $50.00 + $1.00 commission = $51.00 cost but $50.00 value You buy 100 shares of Stock at $500.00 + $1.00 commission = $501.00 cost but $500.00 value Your stock goes up by $2.00 in one year. You buy 1 share of Stock at $5.00 + $1.00 commission = $6.00 cost but $5.00 value You have 1 share now worth $7 = $7.00 You buy 10 shares of Stock at $50.00 + $1.00 commission = $51.00 cost but $50.00 value You have 10 shares now worth $7= $70.