In terms of buying EOS... my caution would be dictated by how much EOS I had.

If I had below my target amount I would price average at these prices (buying a conservative amount every week/ month). I would look for dips in the market to make more substantial buys.

If I had my target amount or more... I would wait for dips before buying.

Re: Cardano. My inclination at present is to wait until the project is further along before taking a decision on whether I should invest. I don't have the time at present to investigate whether it's worth getting in early. The primary reason I invested in EOS early is because Dan Larimer has a track record of delivering useable blockchain technology that can scale. I'd need to see similar evidence from Cardano before getting involved. Getting the right balance between rigorous peer reviewed code and going to market in a timely manner will be key for Cardano.