S&P 500 stock chart putting up resistance

After a big rally, the U.S. stock market is running into “resistance,” a Wall Street term that describes what is akin to a price ceiling the market has trouble cracking after finding buyers at that level in the past.

The Standard & Poor’s 500 has rallied more than 8% since its late August low. But the easy money off the bottom of its first 10%-plus price correction already has been made. Now the benchmark large-company stock index has stalled out around prior price levels that launched rallies in the past.

After a small decline Wednesday, which left the S&P 500 trading at 2019, the index is again stumbling at a key resistance level: the 2040-to-2045 range. Those levels mark the index's average price over the past 100 days and lows touched in March and July, according to Robert Sluymer, a technical analyst at RBC Capital Markets.

The inability to top prior higher levels could be a sign of a stalled or slowing stock advance.

Resistance works like this: If buyers bought in at those levels in the past, only to see stocks fall back below their purchase price, they may be inclined to sell when they get back to even. That selling pressure makes it harder for the market to trend higher — until, of course, it breaks out above that level and investors think there’s money to be made again.

The problem? The S&P 500 made a run at 2040 the past four trading sessions but couldn't take it out. The index closed within 3 points of 2033 the three trading days prior to Wednesday, (and came within 2 points of 2040 Wednesday in intraday trading before closing a tick below 2020), notes Andrew Adams of Raymond James.

The recent price action, Adams told clients in a research note, is a “definite sign of consolidation and possibly of (the rally) stalling out.”

In pre-market trading Thursday the S&P 500 was 11 points higher.