Yes on-topic links are fine.

Also it helps to use Markdown to hide the links - put square brackets around the title followed immediately by round brackets around the link - just experiment with it when you are typing in comments.

so instead of: https://steemit.com/cryptocurrency/@ibringawareness/don-t-panic-re-whales-dumping-steem-dollars-crashing-and-why-the-future-of-steemit-is-worth-betting-on-all-this-in-non-technical

you would have: here is my link

Give it a go it's really easy.