Keep your cash rather than avoid paying PMI?

[Bob Ross]

Is it ever advisable to not pay 20 percent down even if you have the cash to do so?

Let’s say by not paying the 20 percent down requires pay pmi, but instead you choose to keep the money in stocks or just want the money in the bank for repairs or piece of mind.

I was thinking of buying a Multi-Family but would prefer to have a larger cushion when starting out. I figure I may get some returns in s mutual funds or something on the cash. Also I am in effect buying more house (as opposed to buying a cheaper property than would be easier to pay 20 percent down on) and therefore getting more appreciation on the larger amount borrowed. So is it not kind of a wash?

Long story short. Is it ever advisable to not pay 20 percent down to avoid pmi even when you can. Thanks.