Elementary is better than nothing. I followed what the 10yr was doing, and for this situation it worked for me.
My lender does Intra day adjustments, and as I was following what the 10yr was doing during the day(Wed), I saw my lender adjust rates. I went ahead and applied for a loan at 5.125 30 yr fixed. This was when the 10yr was at 3.35 .
This morning my lender has same the 30yr fixed at 6.00.