If you’re new to futures, one of the first choices you’ll face is which size contract to trade. The same market, the S&P 500 say, comes in more than one size, and picking the wrong one is how small accounts blow up on a single trade. The two sizes most retail and prop traders use are the E-mini and the Micro E-mini, and the difference between them is simple to state and important to get right: the Micro is one-tenth the size of the E-mini.
The short version: an E-mini contract controls ten times the value of a Micro, so each tick is worth ten times as much, $12.50 versus $1.25 on the S&P 500. That single fact ripples through everything, how much margin you need, how much you make or lose per point, and how precisely you can size a position. Here’s how the two compare and how to think about which fits your account and your evaluation.
A Quick Note on Names
“Mini” in modern futures almost always means the E-mini, the mid-sized contract CME Group introduced in 1997 to open index futures to individual traders. The Micro E-mini arrived in 2019 at exactly one-tenth the E-mini’s size, built for smaller accounts and finer position control. So when traders say “micro vs mini,” they usually mean Micro E-mini versus E-mini. The original full-size pit contracts still exist for some markets but are rarely what retail or prop traders touch.
The Core Difference: Contract Size
Everything starts with contract size, the multiplier that turns an index level into dollars. The E-mini S&P 500 is $50 times the index; the Micro E-mini is $5 times the index. At an index level of 6,000, that’s a notional value of about $300,000 for one E-mini versus about $30,000 for one Micro. The tick size is identical, 0.25 index points, but the tick value differs by the same 10:1 ratio: $12.50 per tick on the E-mini, $1.25 on the Micro.
| Feature | E-mini (ES) | Micro E-mini (MES) |
|---|---|---|
| Contract size | $50 × index | $5 × index |
| Notional value (index at 6,000) | ~$300,000 | ~$30,000 |
| Tick size | 0.25 points | 0.25 points |
| Tick value | $12.50 | $1.25 |
| Settlement | Cash | Cash |
| Trading hours | Same | Same |
What the Size Difference Changes
The 10:1 ratio is the whole story, and it shows up in four practical places.
Profit and loss per move. A 10-point move in the S&P 500 is worth $500 on one E-mini and $50 on one Micro. Ten Micros equal one E-mini in both exposure and dollar value, exactly.
Margin. Because a Micro controls a tenth of the value, it needs roughly a tenth of the margin. Day-trading margin at many brokers runs around $500 for an E-mini versus around $50 for a Micro, though these figures vary by broker and market conditions.
Position-sizing precision. Micros let you scale risk in much smaller steps. If you want to trim 30% of a position, you can’t do that cleanly with two E-minis, but with twenty Micros you can close exactly six. That granularity is why many traders test strategies in Micros before scaling up.
Spreads and cost. The E-mini is one of the most liquid contracts in the world, with a consistent one-tick spread. Micros have strong liquidity too but can show a slightly wider spread of one to two ticks. Commissions are charged per contract, so trading ten Micros to match one E-mini usually costs more in total fees than the single larger contract.
Why Position Sizing Is the Real Decider
The most useful way to choose isn’t liquidity or prestige, it’s whether you can place a sensible stop without risking too much. Take the common rule of risking about 1% of the account per trade. On a $10,000 account, that’s $100. With a Micro at $5 a point, $100 buys you a 20-point stop, which is workable. With an E-mini at $50 a point, that same $100 only allows a 2-point stop, which is far too tight for most strategies and forces you to either over-risk or get stopped out by noise. This is the core reason small accounts belong in Micros: the contract size has to match the stop distance your strategy actually needs.
Which One Fits You
There’s no universally “better” contract, only the one that fits your capital, strategy, and stage. Beginners and anyone testing a new approach usually start in Micros, where mistakes cost a tenth as much and sizing is flexible. Active day traders and scalpers with larger accounts often prefer the E-mini, where the consistently tight one-tick spread matters more on high-frequency trades. Many experienced traders use both together, holding a core position in E-minis and adding or trimming with Micros for precise control. One handy point for small accounts: futures aren’t subject to the pattern day trader rule, so you can day trade either size without the equity minimum that applies to stocks.
Why This Matters in a Prop Account
Contract choice is one of the most direct risk controls you have in a futures evaluation. Because each tick on a Micro moves your profit and loss by a tenth of an E-mini tick, trading Micros lets you take a position while staying well clear of your daily loss limit and drawdown. On a smaller funded account, a single E-mini can represent more risk per tick than the account can absorb, so Micros are often the only contract that lets you size a trade properly against the rules.
Many firms also set contract limits by account size and let those limits grow as the account does, so understanding the E-mini-to-Micro ratio helps you read a firm’s scaling plan and stay within it. The practical takeaway is the same as for any small account: match the contract size to the risk your rules allow, and use Micros when an E-mini would put too much on the line per trade.
Bottom Line
The Micro E-mini and the E-mini track the same markets with the same tick size and trading hours, and the only real difference is scale: the Micro is one-tenth the size, so its tick is worth $1.25 against the E-mini’s $12.50. That ratio decides your margin, your profit and loss per point, and how precisely you can size and stop a trade. Smaller accounts and newer traders generally belong in Micros, larger and faster traders lean on the E-mini’s tighter spread, and in a prop evaluation the right contract is simply the one that lets you place a proper stop without crowding your loss limits.
Frequently Asked Questions
What’s the difference between a Micro and an E-mini future?
A Micro E-mini is exactly one-tenth the size of the corresponding E-mini. They share the same tick size, trading hours, and underlying market, but the Micro’s tick value is a tenth, $1.25 versus $12.50 on the S&P 500, so it carries a tenth of the risk and margin per contract.
How many Micros equal one E-mini?
Ten. Ten Micro E-minis match one E-mini in both market exposure and dollar value, and that 10:1 ratio holds consistently across every price move.
Which should a beginner or small account trade?
Micros, in most cases. For accounts under about $10,000, the Micro’s smaller size lets you set a sensible stop and risk only a small percentage per trade, whereas an E-mini often forces a stop that’s either too tight or risks too much capital.
Do Micros have enough liquidity?
Yes. Since their 2019 launch, Micro E-minis have built strong retail liquidity, with competitive spreads of one to two ticks. For individual traders, liquidity is rarely a problem, though the E-mini’s one-tick spread is still the tightest.
Why do Micros matter for prop traders?
Contract size is a primary risk control in an evaluation. Trading Micros moves your profit and loss in smaller increments, which helps you stay clear of your daily loss limit and drawdown. On smaller funded accounts, a single E-mini may carry more risk per tick than the rules can absorb.