The S&P 500 could be on the verge of a big breakout, technical charts indicate. The index has been stuck within a “symmetrical triangle,” formed by a pattern of rising pivot lows and falling pivot highs. As the upper and lower boundary lines narrow, it is just a matter of time before a big breakout occurs. The S&P 500 gained as much as 0.70% during intraday trading on Monday to come within striking distance of the declining trend line, before retreating to close up 0.50%. Since “triangles” act as both continuation and reversal patterns, traders need to keep an eye on the direction of breakout. A strong daily close above the 50-day moving average near 2160 could set the stage for record highs with some resistance expected at the August high of 2195.