Shares of Zscaler (ZS) - Get Report  were crushed, closing lower by 19.4% at $49.67 in Wednesday's session. 

Given that the stock was down almost 30% from its highs coming into the report, many bulls were likely hoping for a better reaction to the quarterly numbers.

Fiscal fourth-quarter earnings of 7 cents per share beat estimates by 5 cents per share, while revenue of $86.1 million jumped 53.3% year-over-year and beat estimates by more than $3 million. However, guidance missed the mark.

Management's fiscal first-quarter earnings came up a bit short, while the midpoint of its full-year outlook for both sales and profits were slightly below consensus estimates. Some may argue that the stock's near-20% pummeling is overkill -- and perhaps they're right.

After all, the stock is up notably from its lows of the day, after shares hit $46.04. However, investors still find themselves in a tough spot with Zscaler stock.

Trading Zscaler Stock

Daily chart of Zscaler stock.

Before Wednesday's break down, Zscaler stock was flashing some warning signs. The stock closed below its 200-day moving average on Monday and was again rejected from it on Tuesday. And again, that action came after the stock had already fallen rather precipitously over the last month and a half.

The saving grace to losing its 200-day moving average had been the 50% retracement, which came into play near $60. However, ZS stock gapped below both on Wednesday.

But none of that matters after Wednesday's move; so what's the play?

Nimble bulls who want to trade Zscaler stock can do so with a stop-loss just below Wednesday's low. I generally do not like to buy on day-one of such a fall, but this level proved there are buyers who support it at that price.

Further, $46 was the breakout level in January that sparked the big run to $90.

If ZS stock continues higher, see that it can reclaim $51 -- the February breakout level -- and then the 61.8% retracement at $53.19.

Should $46 fail to support the stock, a decline down into the $42.50 to $43.50 area can take place. That's where Zscaler stock finds a big breakout level from 2018, as well as the 78.6% retracement.

Remember, trading is a series of "if then" statements. "If" support holds, "then" traders can stay long ZS stock. If it can't, we need to wait for it to reset.

This article is commentary by an independent contributor. At the time of publication, the author had no positions in the stocks mentioned.