Here we are in the dog days of summer, and the hot weather is not the only thing making us a little queasy. The darling stock market group since 2011, the Nasdaq 100 stock index, has soared a cool 20% this year and well into all-time high territory. Indeed, the height is making us queasy from vertigo.

It wouldn’t be such a big deal if it weren’t for the nearly 30% outperformance of the Nasdaq 100 compared to the average US large cap stock so far this year. That’s right, while precious few (mostly) tech-related stocks are up about 20%, the equal weighted S&P 500 is down 8%.

Outperformance of tech vs the broad market is nothing new. It’s been happening since 2002. What is out of the ordinary currently is the magnitude of recent outperformance that pushed the relative ratio between the Nasdaq 100 and the equal weight S&P 500 to fully 27% above it’s 200-day moving average. This is…troubling…since the last time it happened was back in 1999.

But it doesn’t end there. The Nasdaq 100 is even extended relative to its own trend. Currently, the index 20% above its own 200-day moving average. This is a scenario that has happened only twice in the last 20 years: once in 2009 and once in 2003. Granted, both of those were notable periods in that the economy was emerging from recessions, just like today. But, in both cases the Nasdaq 100 ended up dropping back below that 200-day average over the months that followed. In other words, it would fit nicely with history for the Nasdaq 100 to take a breather here, and possibly give back some of those tremendous year-to-date gains.