Recent data points are shaking my confidence in the near-term outlook for semiconductor stocks.

After being bearish for more than a year I had turned cautiously bullish earlier this year because it looked like potential supply (which I measure as orders for new semiconductor equipment) was coming back in line with demand (which I measure as the year/year change in semiconductor revenues. Unfortunately, the latest data show this trend weakening faster than I thought it would.

On Monday, the Semiconductor Industry Association (SIA) released their sales report for October, saying worldwide semiconductor sales rose to $23.1 billion, an increase of 5 percent over the $22 billion reported in October 2006 and 2 percent higher than the $22.6 billion reported in September of this year.

That 5.0% sales increase year/year was a slight decline from the 5.8% year/year growth reported a month ago but was still the second-best growth reported since January. Taken alone, I wouldn’t consider this report troubling in terms of the supply/demand balance as it shows stable if not slightly improving demand trends.

However, on November 15 Semiconductor Equipment and Materials International (SEMI) released their October book/bill report for semiconductor equipment orders and sales. The bookings figure was flat with the final September 2007 level of $1.24 billion and 16 percent less than the $1.47 billion in orders posted in October 2006.

The fact that demand growth (up 5%) was greater than supply growth (down 16%) is generally supportive of positive performance for semiconductor stocks. The performance of the SOX index during the last five periods in which such conditions prevailed is presented below.

Sources: SIA, SEMI, William A. Trent

In each of the periods other than 2001/2002 the excess demand growth relative to supply resulted in positive returns for the SOX. Unfortunately, the current period to date most resembles 2001/2002.