D2 player here...played PoE for about 4 hours several years back but haven't done so since...

I would describe in-game trading in d2 as extremely tedious. I would say that most people I encounter in D2 use JSP, as a means of a more fluid transaction/exchange process.

Is there an in-game economy in PoE? How is trading conducted? Is it similar to d2? Is there an auction house?

Does more trading happen in-game in PoE versus D2? Or does the majority of trading take place on JSP (or steam or some other, similar, venue?).

Thank you.

you place your item on a premium stash tab and put a price, it'll get listed on trading site and people will see it from there and contact you directly in game to do the trade

Or... If you don't have premium stash tab, you can make a thread with all your items for trade and it'll get posted onto trade site too, but very tedious this method

Ok, so from what I gather, the only form of in-game trading is thru a "premium stash tab" and once you put your items in there (I'm assuming its like the stash in d2), they get 'listed on a trading site'?

So, in other words, this is completely different than d2 and there is no auction house?

thats correct

its way better than d2 trading either way you look at it. its definantly worth dropping some money on premium tabs because u can list each tab what price u want for everything in the tab or price them individually. its not the most efficient trading system but it works fine

ding ding you got it

Premium stash tabs or a 3rd party tool such as acquisition.
You can also trade the "diablo 2 way" by preparing a trade here on jsp or using a tradechat to find stuff you want.

Premium tabs are the easiest solution and not that expensive either.

vouch for premium tabs

so much more QOL compared to third party tools like aquisition ...

I actually prefer acquisition for most items except maps in the 1-5c range cause it gives information like how long the item has been out and how long its been since Ive updated its price.