With this being said, Wall Street's bull market is on the cusp of unwanted history. Arguably, the best valuation tool that allows for the clearest apples-to-apples comparisons is the S&P 500's Shiller ...

Many investors keep a close eye on Berkshire Hathaway's 13F filing since the conglomerate is run by none other than Warren ...

Wall Street edged back from an all-time high following mixed profit reports from big companies. The S&P 500 barely budged on ...

While this is the type of history investors love to see Wall Street make, the current bull market is also knocking on the door of something that's been historically troublesome. Image source ...