Sorry @XForceOne , you are mixing up P/E with Return on Equity...

Sorry @XForceOne , you are mixing up P/E with Return on Equity (ROE) and then purporting to give everyone investment advice when it should be DYOR.

If you do this again with the right calculations, you come up with a completely different picture (buy Roger Montgomery's book if you need to know how to calculate this).

I'll leave you to do this in the privacy of your own home as it seems to me you're clearly trying to influence other investors by saying "it wouldn't make much sense". So please feel free to invest your precious $100 in any Australian bank for the 1% ROE that they offer if you are lucky. And next year you will have $101.

The P/E ratio is merely what the market is prepared to pay for a high ROE company which I think MSB will be, and I would bet the P/E will be at the very high end for a company that can take death off the table in a global pandemic.