Invalid Formula Operator

This error appears when the expression after = does not match the supported operator set for TradersPost formulas. The sections below are the authoritative definition of what you may write.

Supported operators and syntax

• Arithmetic: +, -, *, /, % (modulo).
• Comparison: ==, !=, <, >, <=, >=.
• Logical: and, or, not (and the equivalent &&, || where applicable).
• Ternary: ?:.
• String concatenation: ~.
• Containment: in, not in.
• References: payload values are read only as signal.<topLevelKey> (for example signal.limitPrice). Nested takeProfit / stopLoss sub-fields use the same expression language with the same operator set.
• Rounding modes: the optional third argument to round() may use rounding.<mode> (for example rounding.halfEven). See invalid formula reference.

Expressions are limited in length (see invalid formula length). Results must be a single scalar (see invalid formula result).

Typical error detail (webhook log)

The log names the field and repeats the supported operator summary so you can align your formula with it.

Examples using only supported operators

Prefix-style check with comparison and literals:

{
  "ticker": "SPY",
  "action": "buy",
  "x": "=signal.ticker == \"SPY\""
}

Numeric result from arithmetic on payload numbers:

{
  "ticker": "SPY",
  "action": "buy",
  "closePrice": "450.25",
  "limitPrice": "=signal.closePrice + 0.5"
}

Large power expressed with multiplication (same operator set, repeated *):

{
  "ticker": "SPY",
  "action": "buy",
  "x": "=2*2*2*2*2*2*2*2*2*2*2*2*2*2*2*2"
}

Membership check with in:

{
  "ticker": "SPY",
  "action": "buy",
  "venue": "NYSE",
  "x": "=signal.venue in [\"NYSE\", \"AMEX\"]"
}

For a full overview of where = is permitted on the payload, see invalid formula syntax.