In a irrevocable trust would there be any capital gains to report to IRS when stocks are sold but the money stayed in the trust?

[Anonymous_]

"...would there be any capital gains to report to IRS when stocks are sold but the money stayed in the trust?"

Yes, capital gains would have to be reported regardless of whether or not the proceeds from the sale of stocks remained in the trust. 

[sunnybrook2002]

Does the cost basis for stock start the day it is  put in the irrevocable grantor trust?

[Anonymous_]

No, if the grantor, while living, merely transfers the stock to the trust, then the trust takes the grantor's basis (carryover basis). Note that the basis is the fair market value on the date of death for property acquired from a decedent.