Why is JPMorgan Chase tightening lending to 20% and 700 score?

[Marcus Auerbach]

Chase requires new home buyers to put 20% down and have a 700 FICO. I believe the national average is around 7% for first time home buyers. What I don't understand is they still offer their DreamMaker loan with 3% down for low credit scores.

A lot of lenders have been overrun with refinance requests in the last weeks, there is only so much volume they can process. Chase is I think the 4th largest lender - is that why they do that, to reduce volume to the cream of the crop?

From the data I see every day it looks like CV will have very little impact on residential housing: low inventory, high demand, multiple offers - unchanged to this day.

Why did Chase do that? 

Will other large lenders follow?