>The coupon is 0 and the current yield is a dash (-) but Ask Yield to worst and Maturity is 4.472%. Does that mean that you will get 4.742% return on the 6 months for the treasury bill?

Treasury Bills are zero coupon, which means that they do not pay interest.

However, you normally purchase them at a discount to their face value (redemption value). In this case, you can pay $97.752 for a $100 Bill that matures on June 29, 2023. You pay $97.752 now and the Treasury pays you $100 in June.

This $2.248 of profit in six months is equivalent to a 4.742% annual yield. There is no catch - this is the going rate for the US Treasury to borrow $100 from you for six months.