PTC Inc. /zigman2/quotes/202034776/composite PTC +1.98% shares dropped in the extended session Wednesday after the internet-of-things software company's forecast earnings range fell mostly on the low side of Wall Street estimates. PTC shares fell 11% to $52.49 after hours. The company forecast fiscal fourth-quarter earnings of 33 cents to 38 cents a share on revenue of $303 million to $308 million. Analysts surveyed by FactSet estimate 37 cents a share on revenue of $309 million. The company reported adjusted third-quarter earnings of 28 cents a share on revenue of $291.3 million. Analysts had estimated earnings of 28 cents a share on revenue of $290.6 million.