October-April Upmove Getting Tired?

From a big picture perspective, what was conspicuous about April is that the post-October 2011 upmove in the S&P 500 from 1074.77 climbed to a new high at 1422.38, marginally above the March high at 1419.15.

However, for the first month since October 2011, the SPX failed to close higher than the previous month. In addition, April's new intra-month high was NOT confirmed by a new high in monthly RSI.

If nothing else, this raises a warning flag that the post-October 2011 upmove might be getting a bit tired.