I have 2.3eth and I would like to ask if i should hold my eth or buy 21 NEO. I also have ADA|BTC|XLM should I invest more in those also or just go for one full investment
Never bet on only one project. Diversify risks even if you have a small amount of money. If you follow for some projects you can invest a little bit more, but if you want invest and forget for quite long time just split up your deposit to several same portions. BTW I'd chose EOS rather than NEO.