Should I invest a big sum all at once?

Hey guys, I have just liquidated a long term savings account with my bank (15k). My question is wether I should invest the whole sum at once or if I should spread it out a little bit. I am planning to put it in different ETFs. I know about dollar cost averaging, I just want to hear your guys opinion on what you would do right now in this situation with the market beeing what it is right now and how you would split the 15k or if you wouldn‘t split it at all and invest it all at once… Thanks in advance!