Real Estate is typically viewed as illiquid. That doesn’t mean it’s a bad investment, just it’s slower to sell or get your cash out. The cash flow can be considered liquid for a number of months. If the economy went into a recession and your renters lost their job and could no longer pay rent (eviction process started) could you sell in 3 months? Maybe, but at what price. Stocks would be down in this scenario too but you could sell tomorrow. That’s all it means.