Buy from 1 Share, and Fractional Shares
US stocks have no lot requirement, so you can buy just 1 share; many brokers also let you buy fractional shares by dollar amount, so a few dollars can own a slice of an expensive stock.
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Text version · US Stock Rules, lesson 5: “Buy from 1 Share, and Fractional Shares”
US stocks have no lot requirement, so you can buy just 1 share; many brokers also let you buy fractional shares by dollar amount, so a few dollars can own a slice of an expensive stock.
You can buy just 1 share
US stocks have no lot requirement: you can buy 1 share or 7. The round lot in market data has traditionally been 100 shares, which only affects how quotes are shown.
Fractional shares: buy by amount
Many brokers support fractional share: you order by dollar amount, say $10 or $100, and get part of a pricey stock. It's a broker feature, not an exchange rule.
Limits of fractional shares
Whether fractional shares can be moved to another broker, carry shareholder votes or be bought with limit orders varies by broker. Read your broker's terms before ordering.
Key takeaways
- US orders have no whole-lot requirement: 1 share or 7 shares are both fine.
- Many brokers support fractional shares: you order by dollar amount, for example $10 buys part of a stock. This is a broker feature, not an exchange rule.
- In quotes, a “round lot” has traditionally been 100 shares; this only affects how quotes are displayed and doesn't limit retail orders.
- Whether fractional shares can be transferred to another broker or carry voting rights differs by broker, so check before you order.
Try it yourself
You can do these exercises in this lesson's interactive simulation:
- Share price $900, budget $300: how many whole shares can you buy?
- Switch to “fractional shares”: how many shares does the same $300 buy?
- Set the share price to $50: how many whole shares can you buy, and how much is left?
Quiz and explanations
- 1. A stock is $900 a share and your budget is $300. How many whole shares can you buy?
- Answer: 0 shares.You can't afford 1 whole share at $900; either wait until your budget is enough or use your broker's fractional-share feature.
- 2. With the same $300 budget, roughly how much of this stock can you buy with fractional shares?
- Answer: 0.33 share.Fractional shares are bought by dollar amount: 300 ÷ 900 ≈ 0.33 share.
- 3. Who provides fractional-share trading?
- Answer: Each broker's own feature.Fractional shares are a broker service; the stocks covered and the rules differ from broker to broker.
Terms in this lesson
- board lot (Board Lot): The exchange's minimum trading unit. A-shares and Japanese stocks trade in lots of 100 shares, each Hong Kong stock sets its own, a Taiwan lot is 1,000 shares, and US and Korean stocks can be bought from 1 share.
- fractional share (Fractional Share): A portion of a share smaller than 1, such as 0.25 shares. Many US brokers let you buy by dollar amount (for example $10 for part of a share); it's a broker feature, not an exchange rule.
- round lot (Round Lot): The standard number of shares in one lot for quotes, traditionally 100 for US stocks. It only affects how quotes are shown; retail investors can buy 1 share or 7.