What Tool should I store my capital in?

[John Hunt]

My wife and I should be debt free and have a 3-month emergency fund by February 2021. We live in the Nashville area and are interested in buying investment property in one of the neighboring towns. We are primarily interested in the BRRRR method.

Once we have our debt paid and E-fund secure, in what vessel would you suggest storing money we're saving for investments? Is the stock market too risky for this? Would it be better off in a high-interest savings account? Something else? 

Thank you in advance for all advice!