You can start investing with $1 at some investment platforms. An investment platform is a company that holds your investments and carries out your orders. Fidelity, a US platform, says it sells parts of a share from $1. At a platform that sells only whole shares, the smallest sum is the price of one share. That was $778.01 for SPY (the S&P 500 exchange-traded fund, or ETF) at the 13 October 2026 close.
The S&P 500 is an index of about 500 large US companies. An ETF is a fund, a pool of money that holds many investments, that trades on a stock exchange like a share. Three minimums can set the smallest sum: the platform's, the fund's and the price of one share. Charges are a separate cost on top. Here is each, with arithmetic on small sums.
How much money do I need to start investing? The smallest published sum is $1, at some investment platforms. A platform is a company that holds your investments. Where only whole shares are sold, the smallest sum is the price of one share.
Fidelity and Schwab, two US platforms, list no account minimum. Fidelity sells parts of a share from $1. One whole share of SPY, the S&P 500 ETF, cost $778.01 on 13 October 2026.
Vanguard's S&P 500 mutual fund, which is bought from the fund company, asks for $3,000.
A dealing charge is the fee a platform takes each time you buy or sell. AJ Bell, a UK platform, charges £5.00 for a share deal. In pounds, that is 5% of £100 but 0.05% of £10,000.
What is the minimum to start investing?
Three minimums set the smallest sum:
The platform's account minimum: the least you must pay in to open the account.
The fund's own minimum: the least some funds accept from a new investor.
The price of a share: the least that buys one whole share, where parts of a share are not sold.
Charges do not set a minimum. They are a cost on any sum: the dealing charge each time you buy. The other is the fund's yearly charge.
Each figure below comes from the company's own page, read on 14 October 2026. The SPY price is its 13 October close. The sums are illustrative arithmetic on those figures, not a recommendation. Our guide to how to invest in stocks covers the whole process.
Platform minimums: Fidelity, Schwab and AJ Bell
Fidelity's page on fractional shares says there are zero account minimums and zero account fees to open an account. It also lists zero commissions for online US stock trades and most ETF trades. A commission is a fee for each trade.
Schwab, another US platform, lists $0 online equity trade commissions on its pricing page, with no account or trade minimums.
AJ Bell, a UK platform, lists regular investing from £25 a month with no dealing charges. Regular investing means a monthly purchase into selected investments. AJ Bell's charge for a one-off share deal is £5.00.
A zero account minimum does not remove the other minimums. The next ones are the fund's and the share's.
The smallest sum by route: parts of shares, whole shares and fund minimums
Source: Fidelity; Vanguard; YX Insights
Chart 1 shows the smallest sum for each route, in dollars. VOO (the Vanguard S&P 500 ETF) lists a $1.00 minimum on Vanguard's own page.
Where a platform deals only in whole shares, the smallest sum is the price of one share. VOO's market price was $715.20 on 13 October 2026. SPY closed at $778.01. Each fund sets its own share size, so the lower price is not a cheaper fund.
Vanguard's S&P 500 mutual fund (VFIAX) lists a $3,000 minimum. A mutual fund is bought from the fund company at one price a day, as Index Funds vs ETFs explains.
A fractional share is a part of one share. Fidelity says you enter a dollar amount and it works out the fraction. This covers stocks and ETFs listed on the New York Stock Exchange or Nasdaq. Our guide to what an ETF is shows how SPY trades.
The table applies the SPY price of $778.01 to four sums in dollars.
Sum | Whole shares it buys | Cash left over | Parts of a share allowed |
|---|---|---|---|
$100 | 0 | $100.00 | 0.1285 shares |
$500 | 0 | $500.00 | 0.6427 shares |
$2,000 | 2 | $443.98 | 2.5707 shares |
$10,000 | 12 | $663.88 | 12.8533 shares |
With whole shares only, $100 buys none. With parts of a share, the same $100 buys 0.1285 of one. A sum of $10,000 buys 12 whole shares, which cost $9,336.12.
Dealing charges: how a flat fee behaves on a small sum
Source: AJ Bell; YX Insights
Chart 2 divides AJ Bell's flat charges for one-off deals by the sum bought. The sums in this section are in pounds, as are AJ Bell's charges. Its page lists £5.00 for a share deal, a group that includes ETFs. It lists £1.50 for a fund deal.
A flat charge stays the same whatever the sum. So £5.00 is 5% of £100 and 1% of £500. It falls to 0.25% of £2,000 and 0.05% of £10,000.
The £5.00 charge reaches 1% of the sum at £500. A flat charge weighs most on the smallest purchases.
Fidelity and Schwab list $0 commissions for online US stock trades, so a flat commission does not arise there. Every trade still crosses the bid-ask spread, the gap between the price buyers pay and sellers receive. What Does a Market Maker Do? explains it.
Ongoing fund charges: 0.0945% a year is 9.45 cents on $100
A fund's yearly charge, called the expense ratio or ongoing charge, is taken from the fund's assets as a percentage. SPY's page lists 0.0945%. Vanguard's pages list 0.03% for VOO and 0.04% for VFIAX.
On $100, SPY's charge is 9.45 cents a year. On $10,000, it is $9.45. Our guide to what an index fund is explains how fund charges work.
Platforms can add their own yearly charge. AJ Bell lists 0.25% a year for holding shares, up to £3.50 a month. On £100, that is 25 pence a year.
The two kinds of charge differ in how they add up. A flat dealing charge of 5% of the sum is paid once. A yearly fund charge of 0.0945% takes about 53 years to add up to the same share of the sum. The ratio holds in any currency and for any platform.
How to read a minimum
A few checks turn a quoted minimum into a smallest sum:
Which minimum it is. An account minimum, a fund minimum and a share price are different numbers.
Whether parts of a share are sold. If they are not, the share price is the smallest sum.
The dealing charge as a percentage of the sum. A flat charge changes weight as the sum grows.
The yearly fund charge, also as a percentage.
The date. Prices and charges move, so each figure here carries its date.
The smallest published sum was $1. Where only whole shares are sold, it was the price of one share, $778.01 for SPY on 13 October 2026. Charges are a separate cost on top of any sum.
Common questions about how much money you need to invest
What is the smallest amount you can start investing with?
$1 at some platforms. Fidelity lists zero account minimums and sells parts of a US share from $1. Where only whole shares are sold, the smallest sum is one share's price: $778.01 for SPY (the S&P 500 ETF) on 13 October 2026. Vanguard's S&P 500 mutual fund asks for $3,000.
Can you start investing with $100?
Yes, where a platform sells parts of a share. At the 13 October 2026 close, $100 buys 0.1285 of one SPY share. Where only whole shares are sold, $100 buys none, because one share costs $778.01. Fidelity lists $0 commissions for online US stock trades and most ETF trades.
A fractional share is a part of one share. You enter a dollar amount and the platform works out the fraction, as Fidelity describes. At the 13 October 2026 close, $500 bought 0.6427 of one SPY share, which cost $778.01 whole. Fractions mean the share price no longer sets the smallest sum.
Do fees matter on a small amount?
A flat dealing charge takes a larger share of a small sum. One UK platform, AJ Bell, charges £5.00 for a share deal: 5% of £100 but 0.05% of £10,000. Separately, SPY's yearly fund charge of 0.0945% is 9.45 cents on $100.
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