Hi, So I've always played triple and quadruple stops as separate chords really quickly. Recently I listened to a recording of Paganini Caprice No 14 and it really sounds like the violinist is playing all 3 notes at once. Is he really (by pushing hard on the strings away from the bridge) or is it just really quick double stops? Thanks in advance!

you can play the three strings further away from the bridge with a bit of pressure on the bow. i don't know the song personally but i have played one like that.
if you can play them fast enough seperately i guess that could work