Invalid Formula Operator

This message appears when a formula (a value that starts with =) uses an operator TradersPost explicitly disallows:

• ** — exponentiation (use repeated * instead if you need a power)
• .. — ranges
• matches — regular-expression matching

Those three operators are rejected for this error. Prefer these operators instead:

• Arithmetic: +, -, *, /, % (modulo)
• Comparison: ==, !=, <, >, <=, >=
• Logical: and, or, not (and && / || where applicable)
• Ternary: ?:
• String concatenation: ~
• Containment: in, not in
• References: payload values as signal.<key> (for example signal.limitPrice), including nested objects with dot or bracket notation (signal.extras.ATR or signal.extras["ATR"])

Other expression forms may still parse without triggering this message. Syntax and reference problems use different codes (see invalid formula syntax and invalid formula reference).

Invalid examples (these use a disallowed operator):

{
  "ticker": "SPY",
  "action": "buy",
  "x": "=2 ** 10"
}

{
  "ticker": "SPY",
  "action": "buy",
  "x": "=1..5"
}

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

Valid examples using allowed operators:

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

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

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

For where = is permitted on the payload, see invalid formula syntax.