 NEW YORK, April 15, 2021 PRNewswire -- SP Dow Jones Indices will make the following changes to the SP 500, SP MidCap 400, and SP SmallCap 600 effective prior to the open of trading on Tuesday, April 20: SP MidCap 400 constituent PTC Inc. NASD:PTC will replace Varian Medical Systems Inc. NYSE:VAR in the SP 500, and Lattice Semiconductor Co. NASD:LSCC will replace PTC in the SP MidCap 400. Siemens Healthineers AG XETR: SHL acquired Varian Medical Systems Inc. in a deal that closed today, April 15. 