The way words are used gives them their meaning. If "bro" is used differently than "brother" in certain contexts, then they have different meanings in those contexts.

In my experience, it does have different meanings.

One usage makes me think of: "friend", "close friend", "homie", "my guy", "dude", "someone I trust", etc.

Another usage is: "immature", "douchey", "fake", "asshole", etc

But is it actually used differently than brother in this context?

Understand that bro also has a pejorative connotation in some context, but that is not the case here.

If the quote was "we are operating as a fking unlicensed securities exchange in the USA brother." how is the meaning different?

I can see that they have slightly different connotations like thanks versus thank you, but that doesn't mean it it's no longer an abbreviation, which is what the parent poster was claiming

I was pointing out that "Bros" in a company name is exactly an abbreviation for "brother". It is, in effect, a different word than "bro" used in slang.

The usage of [abbreviation for brother, as in company names] is very different than the slang "bro" used to describe undesirable people, but it's not very different than the slang "bro" used in the statement quoted in this tweet -- just literal brothers versus metaphorical brothers.

Ah, yeah with the company names, I think it is simply an abbreviation for "brothers". A bit of miscommunication.

I think bro is always an abbreviation for brother, but sometimes the act of abbreviating is done to save space (like company names) and sometimes to specifically impart informality/metaphor (like TFA). But that doesn't mean the unabbreviated version can't be used metaphorically as well.

In day-to-day use, you would not hear people saying "brother", instead. It just doesn't happen. "Bro", in this context, has evolved.

I have definitely been greeted with "what's up, brother?" several times. And I took it exactly the same as when other people have greeted me with "what's up, bro?" -- the former came from someone a bit older than me, and the latter came from someone my age. Intent was 100% identical as far as I could tell.

That may have been the case, but it does not mean that all such uses are 100% identical.

I get that it is an abbreviation, but does it have new meaning? What meaning or connotation would be lost if a user of the word said brother instead of bro? Would there be confusion?

>Would there be confusion?

No, but it would be unusual. You don't hear people using a term like "crypto brothers", for instance. "Bro" carries a different connotation, and it isn't a positive one in this example.

I don't think it is simply an abbreviation in this case.

In this example, do you think the speaker of the quote was using it in a negative connotation? I think it's pretty clear that that is not the case.

Precisely. The speaker might happen to be "a bro" in the derogatory sense of the word (especially given involvement in an activity that may have a significant population of those people), but that's fairly distinct from simply calling someone "bro" as used in this quote. But I do say "fairly" because bros (in the derogatory sense) probably also call each other "bro" (in the sense that someone is close like a brother) at a rate that exceeds baseline. That elevated rate is probably pertinent to the etymology of the derogatory sense, come to think of it.