With the Fed beating the rate hike drum hard, common sense is that TLT should be sold off from now on given the expectation of higher rate. It will be a surprise (and will tell us something) if TLT continues to hold up from current level.
So far SPY appears to be cheering the perspective of a near future rate hike, or the rally since Feb might just be a countertrend short-squeezed oversold rally.
To put new money into SPY with the backdrop of next Fed rate hike, I must see SPY to make a fresh all time high, and TLT to be sold off. Otherwise I will just keep watching.