Stifel analyst Patrick Ho addressed investor concerns regarding MKS Instruments following the company's recent Q4 earnings release and ahead of the Photonics West conference this week. As the company's revenues begin to rise again, there were concerns that the leverage was not dropping to the bottom line like it did in 2018 when it reported similar revenue numbers, Ho tells investors in a research note. The analyst, however, says this year and 2018 are not completely the same as revenue contribution and mixes are different, and there are some additional moving parts that differed in both years. He believes a combination of factors is placing some near-term pressures on margins, but that structurally, MKS' operating model is intact. As such, the recent share weakness makes the stock more attractive, says Ho, who reiterates a Buy rating on MKS Instruments with a $134 price target.