“I'm out” is the phrase a Dragon commonly says when rejecting a business proposal on Dragon's Den.
During a pitch, an investor may decide that the business, valuation, market or proposed equity does not justify an investment. Saying “I'm out” communicates that the Dragon has withdrawn from consideration and will not make an offer.
The expression became one of the programme's most recognisable pieces of language because it marks a decisive moment in the negotiation. Several Dragons can leave one after another, reducing the entrepreneur's remaining options while the other investors continue asking questions.
It does not necessarily mean the pitch has ended. If at least one Dragon remains interested, the entrepreneur may still negotiate an offer. The phrase is also associated with other versions of the international format, but the British programme made it especially familiar to UK television audiences.