Thunderbolt Classic accounts purchased before October 29, 2026 keep the earlier 20% funded limit and no minimum funded trading days. Use the rules assigned to your account.

Best Day % = largest day’s profit ÷ total net profit in the same payout period × 100.

For the first payout, measure from funding. After a payout, use the new payout period. Losses reduce net profit and can increase the ratio. A new largest day changes both the numerator and the total.

Suppose total net profit is $4,000 and the largest day earned $1,800. The ratio is 45%, above both 35% and 20%, so the condition is not met.

If the largest day stays at $1,800, the mathematical minimum total is $5,142.86 for 35%, or $9,000 for 20%. These are calculation examples, not recommended trading targets; subsequent profits and losses can change the ratio.

The Best Day condition blocks a payout until it is met. It does not itself close the account. You must still respect every drawdown, trade-loss and prohibited-strategy rule while trading.

Meeting the Best Day limit is only one requirement. Thunderbolt Classic also requires its profit threshold and qualifying days; Vanguard requires 6% profit and has no minimum trading days. Horizon has separate profit and day requirements. See Futures payout conditions for the complete checklist.

Does it apply in the challenge? Current Thunderbolt Classic and Horizon Futures challenges have no Best Day Rule. Vanguard has no challenge phase.

Can small trades count? Trade size does not change the ratio calculation. Where qualifying days are required, each day must separately earn the minimum profit specified by the program.

Does exceeding it lose the account? No. It is a payout condition; hard risk limits remain separate.

See soft and hard breaches and how to request a payout.