@Critter-3 

Yes he needs to file the 1099Bs.  Be sure on his return he checks the box that says he can be claimed on someone else's return.  Go up to File-New.

You do not report his income on your return*. If it has to be reported, at all, it goes on his own return. If your dependent child is under age 19 (or under 24 if a full time student), he or she must file a tax return for 2022 if he had any of the following:

1.          Total income (wages, salaries, taxable scholarship etc.) of more than $12,950 (2022).
2.          Unearned income (interest, dividends, capital gains, unemployment, taxable portion of 529 distribution) of more than $1150 (2022)
3.          Unearned income over $400 (2022) and gross income of more than $1150 (2022)
4.          Household employee income (e.g. baby sitting, lawn mowing) over $2300 ($12,950 if under age 18)
5. Other self employment income over $432, including money on a form 1099-NEC

If none of the 1099-Bs show a gain of more than $1150, technically he does not need to file a tax return. But he may want to file anyway to head of an IRS inquiry and to document his capital loss carry forward. 

*If his only income is from interest and dividends, Alaska PFD or capital gains distributions shown on a 1099-DIV, there is a provision for entering it on your return, using form 8814. The fact that he has a 1099-B prevents you from using this option