Short-sellers hate being caught short a stock that reports a blowout quarter. When this happens, we often see a tradable short squeeze develop as the bears rush to cover their positions. Even the best short-sellers know, it's never a great idea to stay short once a bullish earnings report sparks a big short-covering rally.

This is why I scan the market for heavily shorted stocks that are about to report earnings. You only need to find a few of these stocks every week to help enhance your portfolio returns.

With that in mind, let's take a look at several stocks that could experience big short squeezes when they report earnings this week.

YY

My first earnings short-squeeze trade idea is China-based online social platform operator YY (YY - Get Report) , which is set to release numbers on Tuesday before the market open. Wall Street analysts, on average, expect YY to report revenue of $352.03 billion on earnings of $1.03 per share.

The current short interest as a percentage of the float stands at 8%. That means out of the 32.68 million shares in the tradeable float, 2.61 million shares are sold short by the bears.

I would wait until after YY reports, and then look for long-biased trades if this stock manages to break out above some near-term overhead resistance levels at $52 to $53, with volume that hits near or above 767,262 shares. If that breakout fires off post-earnings, this stock will set up to re-test or possibly take out its next major overhead resistance levels at $55.50 to $57.20, or even its 52-week high of $63.96 a share.

Inovio Pharmaceuticals

Another potential earnings short-squeeze trading opportunity is clinical stage biopharmaceutical player Inovio Pharmaceuticals (INO - Get Report) , which is set to release numbers on Wednesday after the market close. Wall Street analysts, on average, expect Inovio Pharmaceuticals to report revenue of $5.95 million on a loss of 30 cents per share.

The current short interest as a percentage of the float for Inovio Pharmaceuticals is very high, at 14.7%. That means out of the 68.96 million shares in the tradeable float, 10.19 million shares are sold short by the bears.

I would wait until after Inovio Pharmaceuticals reports, and then look for long-biased trades if this stock manages to break above a downtrend line that will trigger over its 20-day at $6.84 and then above $7.23, with volume that hits near or above 836,428 shares. If that breakout triggers post-earnings, this stock will set up to re-test or possibly take out its next major resistance levels at $7.64 to $8, or even its 200-day at $8.24 to $8.50 a share.

Amphastar Pharmaceuticals

Another potential earnings short-squeeze candidate is specialty pharmaceutical player Amphastar Pharmaceuticals (AMPH - Get Report) , which is set to release numbers on Monday after the market close. Wall Street analysts, on average, expect Amphastar Pharmaceuticals to report revenue of $55.78 million on a loss of 1 cent per share.

The current short interest as a percentage of the float for Amphastar Pharmaceuticals is notable at 6.8%. That means out of the 36.34 million shares in the tradeable float, 2.47 million shares are sold short by the bears.

I would wait until after Amphastar Pharmaceuticals reports, then look for long-biased trades if this stock manages to break out above some near-term resistance levels at $15 to $15.82 with volume that hits near or above 391,420 shares. If that breakout develops post-earnings, this stock will set up to make a run into its previous gap-down-day zone from February that started near $18.50 a share.

Williams-Sonoma

Another earnings short-squeeze prospect is multi-channel specialty retailer Williams-Sonoma (WSM - Get Report) , which is set to release numbers on Wednesday after the market close. Wall Street analysts, on average, expect Williams-Sonoma to report revenue of $1.61 billion on earnings of $1.51 per share.

The current short interest as a percentage of the float for Williams-Sonoma is extremely high at 19.9%. That means out of 73.57 million shares in the tradeable float, 14.65 million shares are sold short by the bear.

I would wait until after Williams-Sonoma reports, and then look for long-biased trades if this stock manages to break out above some near-term resistance levels at $49 to $50.61 with volume that hits near or above 1.30 million shares. If that breakout materializes post-earnings, this stock will set up to re-test or possibly take out its next major overhead resistance levels at $53.50 to $56.50, or even its 52-week high of $61.97 a share.

DSW

My final earnings short-squeeze play is branded footwear and accessories retailer DSW (DSW) , which is set to release numbers on Tuesday before the market open. Wall Street analysts, on average, expect DSW to report revenue of $691.51 million on earnings of 16 cents per share.

The current short interest as a percentage of the float for DSW stands at 10.4%. That means that out of the 64.69 million shares in the tradeable float, 6.72 million shares are sold short by the bears.

I would wait until after DSW reports, and then look for long-biased trades if this stock manages to break out above some near-term resistance levels at $21.40 to $22.50, with volume that hits near or above 1.62 million shares. If that breakout triggers post-earnings, this stock will set up to re-test or possibly take out its next major resistance levels at $23.75 to $25, or even $26 to $27 a share.

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