[constantcrying]

>Is this something that HN does on purpose?

No, the HN algorithm is extremely simple and does not consider syntactic similarities of the titles.

[Solvency]

I've noticed similar themed posts appearing in clusters constantly on HN. It's way too commonplace to be coincidental.

[constantcrying]

No it is coincidental. Look at the algorithm yourself.

[Solvency]

It doesn't mean it's the algorithm, it means users could be tactically posting to ride a wave of similar interest. That's all.

[constantcrying]

Yes, you are right. Potentially the effect is partly due to that after seeing the first post a user stumbles over something related and decides to post that as well.