1.
bullish, optimistic (finance)
In financial markets, the expectation that prices will rise. The opposite of bearish.
2.
confident, assertive, firm
A confident or assertive attitude; not easily intimidated or discouraged.
Usage
1. FINANCIAL/BUSINESS:
2. PERSONALITY/ATTITUDE:
Antonym: 弱気 (bearish; timid, lacking confidence)
Note: 強気 can describe someone who doesn't back down, but in some contexts may have a slightly negative nuance of being overconfident or aggressive.