Shares of Genuine Parts were falling sharply after the distributor of automotive and industrial replacement parts slashed its outlook. Genuine Parts stock declined 18% to $117.85 in on Tuesday, putting the stock on track for its largest daily percentage decrease on record, according to Dow Jones Market Data. For its third quarter, the company reported adjusted earnings of $1.88 a share, missing Wall Street estimates for $2.42, according to FactSet.