Can I buy just one share of a stock?

Yes. There is no minimum number of shares, and one share is a perfectly normal order. You get exactly the same thing per share as a pension fund holding millions: the same dividend per share, the same vote per share, the same price move per share.

And you can go smaller. Most major brokers offer fractional shares, so you can put $20 into a company whose shares cost $600 and own one-thirtieth of a share. Dividends are paid proportionally. The only limitation is that fractional shares usually cannot be transferred to another broker; you would sell them and move the cash.

Historically, brokers charged a flat commission per trade, which made buying one share silly because a $10 fee on a $50 purchase was a 20 percent loss on day one. That is gone at nearly every mainstream broker, which is why buying small now makes sense.

One practical point: with a single share, the bid-ask spread matters a little more in percentage terms, so use a limit order on thinly traded stocks. On big names, it is a cent or two and not worth thinking about.