Here is a brief review of period-over-period change in short interest in the August 1-15 period in nine S&P 500 sectors.

XLB (SPDR materials ETF)

XLB ($59.13) mid-August once again successfully tested support at $57. As if anticipating this, shorts cut back big. Short interest fell 25 percent p/p to under 10 million. This virtually negates any possibility of a squeeze. The ETF is still held down by a falling trend line from late-January highs.

XLE (SPDR energy ETF)

XLE ($74.54) has been under pressure since peaking at $79.42 on May 22. It has since been caught in a descending channel, the lower end of which was tested eight sessions ago, and held. The upper end gets tested around $77. But the ETF needs to first get past the 50-day moving average ($75.10).

XLF (SPDR financial ETF)

XLF ($28.24) cannot get past resistance at $28.50, with the latest rejection having come four sessions ago. As did most US stocks late January-early February, the ETF came under severe pressure, before bottoming in February. But it was not the bottom. Until late June, it kept making lower lows. Short interest has slightly built up over the past seven months, but shorts likely stay put until at least the aforementioned resistance is taken out.

XLI (SPDR industrial ETF)

Mid-July, short interest on XLI ($76.72) rose to a 33-month high. The 28.7-percent drop since has helped the ETF. After bottoming at just south of $71 late June, it rose to $77.46 last Tuesday. There is still room for squeeze, but XLI just retreated from the top of a four-plus-month slightly rising channel.

XLK (SPDR technology ETF)

Shorts are turning tail. They have gotten squeezed – big time. Mid-December last year, short interest on XLK ($74.28) was 38 million. The latest count is 17.5 million – a two-year low. The ETF in the meantime rose to a fresh all-time high of $74.30 last Friday. Bulls are working on forging another breakout. If they succeed, unlike in the past several months, they would have done so without much help from short squeeze.