Shares of application performance monitoring software provider Dynatrace (NYSE:DT) fell 15% in the morning session after the company reported third-quarter results with billings falling below Wall Street's expectations. And while full-year revenue guidance came in higher than Wall Street's estimates, full-year ARR (annual recurring revenue) came in below expectations. Also, its gross margin fell. Zooming out, this was a mixed quarter, but with software stocks that are often expensive from a valu