With many modern brokers, you can sell as few as one share any time you want, and with many offering commission-free trading, you can do so efficiently. Some brokers go a step further and allow you to purchase fractional shares, so you can purchase less than one share.

Yes, though, for most investors, only up to a certain point. If a stock’s trading volume is very low, it can be difficult to find someone to buy or sell shares for when you want to trade. This can dramatically increase the cost of trading that stock. However, for most retail investors, all large cap and most medium-cap stocks, as well as even many small-cap stocks, have more than enough trading volume for your purposes.

The name “Wall Street” comes from a street in downtown Manhattan in New York City where the New York Stock Exchange (NYSE) is located. The importance of the street to the financial industry dates at least as far back as 1792, when the Buttonwood Agreement created the stock exchange.