On the daily chart note the uptrend measured from the end of January is still in tact and would only get seriously violated below $41.50. The last real resistance/support level was around $36.60 in March. A 50% Fibonacci retracement from that level up to the highs comes in around $43.15. As such I see a fairly important support zone between $41.50 - $43.15 that must hold for this most recent uptrend (since end of January) to remain in place.
Also on the daily chart - Candlestick analysis gives us a couple of things to contemplate. First, the dramatic topping doji bar from April 25 has so far held as a top. The rebound over the ensuing days did not make new highs but rather last night was counteracted with the huge drop discussed above. What we will be looking for today is a weak close, i.e, that silver doesn't rally and make back most of the losses today. On a weak close today we would essentialy have confirmation of the April 25th doji, giving us more conviction for a short-side trade and clear stops near $50.
One more level to keep an eye out for is $44.60, which was last week's.