Liquid.trade and a strange fiat deposit scheme via other exchanges

[internetional]

I recently came across a trading platform called Liquid Trade: https://app.liquid.trade

At first glance, it looks like another modern trading interface for crypto perps and other markets. But while checking the deposit options, I found something I had not seen before.

Liquid Trade claims to support deposits not only by card, wire transfer, or crypto, but also through "External Apps". The interface says that you can deposit from more than 100 apps.


The process opened a separate window on the domain connect.swapped.com
I tried to see how this works and selected Bitfinex as the source.


Then it showed a login form: "Log in with Bitfinex", asking for my Bitfinex username and password.


At this point I stopped.

The whole thing looks questionable to me. Liquid Trade presents itself as a non-custodial platform and says it does not hold user assets. But if I "deposit cash" from Bitfinex through this external widget, then where exactly do the fiat funds go?

Do they really move fiat from one trading platform to another?
Does Swapped somehow initiate a withdrawal from Bitfinex?
Is the fiat converted into crypto/stablecoins and then sent to Liquid Trade?
Who is the merchant or final recipient of the funds?
And why should a user enter Bitfinex login credentials on a third-party domain instead of using an official Bitfinex authorization/API flow?

Maybe there is a legitimate explanation. Perhaps this is some kind of account-linking or payment aggregation service that I simply have not encountered before. But to me, asking for the username and password of an exchange account through a third-party window is a major red flag.

Has anyone here used Liquid Trade or Swapped Connect?
Has anyone tried this "deposit from external apps" flow?
How exactly does it work, and where do the funds actually arrive?

I am especially interested in whether anyone has seen this scheme used safely by reputable platforms, or whether this should be treated as a phishing-like pattern.

[rat03gopoh]

I've never used them. I doubt they're an independent exchange. You know the security rules: Don't provide your username and password when prompted by an unauthorized url. If you look at the screenshot, the requested fields are too simple. Your input may not be protected.

You should also consider this in their terms of service:

The operator is not responsible for any transactions on other platforms and disclaims all liability for such transactions.

https://www.liquid.trade/termsofservice#:~:text=The%20operator,-is%20not%20responsible

[logfiles]

This is the first time I am seeing this kind of arrangement. Why would anyone transfer fiat from one crypto exchange to another for a higher fee, yet we have stablecoin options with cheaper withdrawal fees. To me, this total does not make any sense.
I won't test the service... Maybe just with a throwaway account to feed my curiosity..