Pekic | E+ | Getty Images[CK bullet with numbers.]The stock market's impressive run in recent years may be fattening your portfolio, but it also might have thrown your intended investment mix off balance.While artificial intelligence stock valuations spurred a market decline on Tuesday, the major indexes are still well up this year, propelled both by AI-related and big technology stocks. Through Tuesday's close, the S&P index is up about 15.1%. Both the Dow and the Nasdaq have also posted double-digit gains ...