Proto Labs reported September quarter results with a miss on revenue, marking the fourth consecutive quarter with "disappointing" results and downward revisions to estimates, Piper Jaffray analyst Troy Jensen tells investors in a research note. While slowing industrial spending is the main culprit for the downward revision, some of the company's growth initiatives have struggled to gain momentum, says the analyst, who lowered his 2020 estimates to reflect mid single-digit growth. Jensen lowered his price target for Proto Labs to $82 from $88 and reiterates a Neutral rating on the shares. He remains cautious on the stock, noting the multiple has not moved down with consensus estimates.