Since topping out on 4/20 at 2111 and change, the S&P has assumed a downward trajectory as indicated by the yellow channel, a short EMA (8) (shown in red), and a long EMA (34) (shown in green), also putting in a series of lower highs and higher lows. The general notion is to trade in the direction of the prevailing trend (down), so my tendency would be to short on retraces to obvious resistance (e.g., 2064 (shown in green)), the previous upwardly sloping channel's midline (shown in blue), or ideally, the yellow channel's upper bound, since the risk-reward of shorting from apparent resistance at 2064 is currently limited to about 20 handles, give or take ... . (Not that I'd sneeze at 20 handles, but I'd rather have the potential for 50 or so from the channel's upward bound ... ).
For an options trader like me, I am likely to put on short delta via short call credit spreads when SPY's price reaches the top of the yellow channel ... . Naturally, these spreads will be well clear of 209 ... .