pay off house vs stock market investment

[lightspeed]

I have a goal of retiring in 5-8 years. I do have significantly extra cash flow just from living below our means. I can use it to pay off our mortgage in as quickly as 3 years vs dollar cost average into the market, where we have invested approx 1.2 million already. We need about 2 million for me to retire. I'm looking for opinions as to which may be the best strategy in light of the current economic situation. Thanks ahead of time.