Contract Sizing for Vector Strategies: Prop Firm vs. Cash Accounts

Contract Sizing for Vector Strategies: Prop Firm vs. Cash Accounts

DISCLAIMER: Nothing in this article constitutes financial or trading advice. All content is educational and informational only, as outlined in each client's agreement with Vector Algorithmics. Any modification of settings or parameters is made at the client's sole discretion and responsibility.

Category: Trading Operations | Last Updated: April 2026

Contract sizing is one of the few things clients actively decide about when running Vector strategies — most other parameters ship pre-tuned from the Settings Spreadsheet. This article covers how sizing works differently across prop firm and cash accounts, and what to keep in mind as your account evolves.

Disclaimer: Vector does not provide personalized financial or trading advice. The guidance below is general and educational in nature. Your own risk tolerance, account size, and prop firm rules are yours to evaluate. For firm-specific position-sizing rules, always consult your prop firm's own documentation.


Why Contract Sizing Matters

The same number of contracts creates very different exposure depending on the contract:

  • 1 NQ (E-mini Nasdaq-100) = $20 per point
  • 1 MNQ (Micro E-mini Nasdaq-100) = $2 per point — exactly 1/10 the size of NQ
  • Same principle for ES ($50/point) vs MES ($5/point)

See the dedicated article on NQ vs MNQ for the full breakdown and how to avoid accidentally loading the wrong contract on your chart.


Prop Firm Accounts — Why Micros Are the Common Choice

Prop firm accounts work differently from cash accounts in a way that often catches new clients off guard: your account size is not the same as your available risk budget.

Many people confuse the two. A $50,000 prop account doesn't mean you have $50,000 to "absorb" losses — what you actually have is the drawdown limit the firm sets on that account. Depending on the firm, on that same $50,000 account, your practical exposure might be as little as ~$2,000 of drawdown before the account is lost. In other words, the cold math is: you only have room to lose what your firm's drawdown allows — not the headline account balance.

Because of this, running Micros instead of Minis is a common choice on funded prop accounts. Running minis with only a few thousand dollars of effective risk budget means one bad trade can wipe the account; running micros keeps each trade's exposure proportional to what the account can actually absorb. This is how clients avoid overleveraging against the headline number and blowing the account early on.

Evaluation stage — the exception. During evals, some clients choose to run Minis rather than Micros to try to pass faster. That's a legitimate but more aggressive approach and depends on how willing you are to accept the higher risk of failing the eval in exchange for speed. The dedicated article on Tips for Passing Your Prop Firm Evaluation Faster covers the trade-offs. Both micros and minis during eval are accepted paths.

Whatever contract you run on a prop account, stay within your firm's sizing caps — exceeding them is a rule violation.


Cash Accounts Starting Out — Micros at 1 per $10,000 of Balance

Cash accounts behave differently from prop accounts because the account balance is your risk budget (there's no external drawdown limit; you can only lose what you fund). For cash clients starting out with Micros, a common starting point is:

1 Micro (MNQ) contract per $10,000 of account balance, or equivalently 1 E-mini (NQ) contract per $100,000 of account balance (1 NQ = 10 MNQ).

So: - → 0,000 account → 1 micro - $25,000 account → 2–3 micros - $50,000 account → 5 micros

This is a starting point, not a rigid rule. Sizing more conservatively (e.g., 1 micro per $10k) is your call; sizing more aggressively is also your call, but should be done deliberately — not reactively after a good week.


Cash Accounts Running NQ (Minis) — Scaling As You Grow

Clients who've grown their accounts enough to run full-size NQ (minis) face a different question: when and how to scale up.

Toggling between Micros and Minis every $5k of balance change is not a clean approach — mixing contract sizes during normal operation makes performance harder to read and decisions harder to track. A cleaner pattern for clients already running minis and not withdrawing profit:

Add one additional Mini contract for each ~$50,000 of retained profit if you understand the risks and are comfortable with the added exposure — or, for a more conservative pace, add one additional Mini contract for each ~$100,000 of retained profit.

The $50k or $100k threshold keeps each size increase meaningful and avoids constant tweaking — pick the pace that matches your risk tolerance. Results tend to stay more consistent over time with this pattern. If you're withdrawing profit regularly, scaling should slow down or pause accordingly.


Universal Principles

Regardless of account type:

  • Don't size reactively. Changing contract size after a single good (or bad) session — or even a single good week — tends to work against you over time. See the Managing Fear and Greed article for the mindset piece.
  • Stay within your firm's sizing rules (prop accounts).
  • Ask when unsure. Open a support ticket before changing sizing meaningfully so a team member can help you think through the math for your specific setup. Vector doesn't give personalized advice, but we can help you reason about whether a change aligns with how the strategy was designed to operate.


Risk Per Account — MNQ / NQ Reference Tables

The two tables below translate the sizing rule (1 MNQ per $10,000, 1 NQ per $100,000) into concrete contract counts and dollar values across a wide range of account sizes. They’re intended as a quick reference: pick the row that matches your account size, and read across.

Assumptions used in the tables below: Stop Loss = 125 pts · TP1 = 50 pts · TP2 = 80 pts · MNQ = $2 / point · NQ = $20 / point · Target risk per trade = 2.50% · Daily risk limit = 3.50%.

Table A — Position allocation

How many MNQ and/or NQ contracts to run, and how they split across the two take-profit legs (TP1 and TP2).

Account SizeTotal ContractsMNQ ContractsMNQ → TP1MNQ → TP2NQ ContractsNQ → TP1NQ → TP2
$10,00011
$20,0002211
$30,0003321
$40,0004422
$50,0005532
$60,0006633
$70,0007743
$80,0008844
$90,0009954
$100,000101055
$120,000121266
$140,000141477
$160,000161688
$180,000181899
$200,0002211
$250,0007532211
$300,0003321
$350,0008532321
$400,0004422
$450,0009532422
$500,0005532
$550,00010532532
$600,0006633
$650,00011532633
$700,0007743
$750,00012532743
$800,0008844
$850,00013532844
$900,0009954
$950,00014532954
$1,000,000101055

Table B — Stop-loss, take-profit and daily limits (in dollars)

What each row above translates to in actual dollar amounts. Stop-loss represents the maximum loss per trade if your shared SL is hit; the daily limit is the 3.50% cap recommended for any one trading session.

Account SizeStop Loss ($)SL %MNQ TP1 ($)MNQ TP2 ($)NQ TP1 ($)NQ TP2 ($)Daily Limit ($)Daily Limit (%)
$10,000$2502.50%$100$3503.50%
$20,000$5002.50%$100$160$7003.50%
$30,000$7502.50%$200$160$1,0503.50%
$40,000$1,0002.50%$200$320$1,4003.50%
$50,000$1,2502.50%$300$320$1,7503.50%
$60,000$1,5002.50%$300$480$2,1003.50%
$70,000$1,7502.50%$400$480$2,4503.50%
$80,000$2,0002.50%$400$640$2,8003.50%
$90,000$2,2502.50%$500$640$3,1503.50%
$100,000$2,5002.50%$500$800$3,5003.50%
$120,000$3,0002.50%$600$960$4,2003.50%
$140,000$3,5002.50%$700$1,120$4,9003.50%
$160,000$4,0002.50%$800$1,280$5,6003.50%
$180,000$4,5002.50%$900$1,440$6,3003.50%
$200,000$5,0002.50%$1,000$1,600$7,0003.50%
$250,000$6,2502.50%$300$320$1,000$1,600$8,7503.50%
$300,000$7,5002.50%$2,000$1,600$10,5003.50%
$350,000$8,7502.50%$300$320$2,000$1,600$12,2503.50%
$400,000$10,0002.50%$2,000$3,200$14,0003.50%
$450,000$11,2502.50%$300$320$2,000$3,200$15,7503.50%
$500,000$12,5002.50%$3,000$3,200$17,5003.50%
$550,000$13,7502.50%$300$320$3,000$3,200$19,2503.50%
$600,000$15,0002.50%$3,000$4,800$21,0003.50%
$650,000$16,2502.50%$300$320$3,000$4,800$22,7503.50%
$700,000$17,5002.50%$4,000$4,800$24,5003.50%
$750,000$18,7502.50%$300$320$4,000$4,800$26,2503.50%
$800,000$20,0002.50%$4,000$6,400$28,0003.50%
$850,000$21,2502.50%$300$320$4,000$6,400$29,7503.50%
$900,000$22,5002.50%$5,000$6,400$31,5003.50%
$950,000$23,7502.50%$300$320$5,000$6,400$33,2503.50%
$1,000,000$25,0002.50%$5,000$8,000$35,0003.50%

How to read mixed (MNQ + NQ) account sizes: $250k, $350k, $450k, … etc. show both MNQ and NQ columns populated — those accounts run a small MNQ allocation alongside the NQ contracts so the total stop-loss still lands on the 2.50% target. The pure $200k, $300k, $400k, … rows run NQ only.

Bottom Line

  • Prop firm funded accounts → Micros are the common choice because your real risk budget is the drawdown limit, not the account's headline balance.
  • Prop firm eval accounts → Micros or Minis depending on how aggressive you want to be (see eval-passing article).
  • Cash accounts on Micros → 1 Micro per $10,000 of balance as a starting point.
  • Cash accounts on Minis → add one mini per ~$50,000 of retained profit (or ~$100,000 for a more conservative pace).
  • All account types → don't size reactively, stay within firm rules, ask when unsure.