During the month of May 2018, the PS4 outsold the Switch by 215,254 units for the month and the Xbox One by 609,222 units. The Switch outsold the Xbox One by 393,968 units.
When you compare monthly sales to a year ago, the Xbox One and Switch are up, while the PS4 is down. The Xbox One is up 28,284 units, the Switch is up 187,970 units, and the PS4 is down 289,793 units.
Taking a look at the marketshare, the PlayStation 4 managed to achieve 48 percent. The Nintendo Switch accounted for 37 percent of the consoles sold, and the Xbox One 15 percent.