> If I was Instagram I would probably offer a small sum to Bolt.co to change their name on the basis that I could offer a sum now or know I could have a deep reserve of budget for legal fees to
argue that Bolt.co has not developed sufficient goodwill/reputation to be entitled to prevent Instagram's usage of 'Bolt'.
What? That is not at all how trademark works.
If Instagram wanted, it might have a shot at a protracted lawsuit, attempting to make it not worth Bolt's time to defend the trademark [0].
If that were to happen, though, I would hope that the suit would be dismissed with prejudice because in my non-legal opinion, any reasonable person would agree that Instagram is directly infringing Bolt's trademark in an area of business that is too similar for the average consumer to be able to differentiate.
[0] either by bankrupting them if they decide to defend it, or if Bolt can successfully mount a defense, it would require a large time investment by key employees like all the C-level executives, meanwhile Instagram (having more resources by far) is not impeded in its business nearly as much.