The action in the first half augurs well for some follow-through in the July-December period. Probabilistically of course, but anything can and will happen if and when it wants to.
That being said…I believe the below statistics, via BTN Research, are worth thinking about:
SIX DOWN, SIX TO GO – The S&P 500 was up +13.8% (total return) for the first half of 2013 (i.e., January-June), its best performance for the first 6 months of any calendar year since 1998. The stock index gained +17.7% for the first half of 1998, on its way to a +28.6% gain for all of 1998.
AND THEN? – The S&P 500 gained +13.8% (total return) for the first half of 2013, the 16th time since 1990 (i.e., 16 of 24 years) that the stock index has produced a positive total return during the January-June time frame. In the previous 15 times that the S&P 500 was positive during the first half of the year, the stock index followed up with a positive total return in the second half of the year 12 times, i.e., 80% of the time.
THE HOME STRETCH – The S&P 500 has closed at its calendar year high in the second half of the year (i.e., during the 6 months of July-December) 73% of the time since 1950.
80%, 73% – I like those precedents, although I’d not be betting my life on them.