From Bespoke Investment Group:

With the overall stock market approaching new bull market highs, the number of new 52-week highs in the S&P 500 is expanding rapidly. As shown below, the net new highs indicator has come to life on the positive side after remaining stagnant for a few months.

Because the year-over-year change in the market remained very negative up until just recently, stocks were not hitting new 52-week highs even though the market had been rallying strongly.

Now that we're above levels that we were at one year ago, we're getting numerous 52-week highs on a daily basis. This is to be expected and will remain a bullish sign as long as the number continues to expand.

Read full article (with charts)...

More on stocks:

A shocking look at the stock market's real gains

Top asset manager sees a sharp correction coming

Value legend Mohnish Pabrai on the best stocks to own today