Looking for legitimate ways to reduce a large 2026 stock capital gains tax bill without taking unnecessary investment risk

I had a significant stock gain in 2026 (mostly short-term 500k approx ), but some positions I reinvested in have since declined and are currently at a loss.

I’m looking for legitimate tax strategies to reduce my 2026 tax bill, especially strategies that don't require taking excessive investment risk.

I’ve heard about things like:

• Tax-loss harvesting
• Oil & gas investments / gas bonds
• Car wash or other businesses using depreciation
• Real estate/cost segregation
• Opportunity Zones

For those familiar with these strategies:

Which ones can actually help offset stock gains, and which are mostly marketing or too risky?

I’m not interested in charitable strategies. Ideally, I’d like something where the investment itself makes economic sense even without the tax benefit.

Any recommendations on what I should discuss with a CPA/tax attorney?