The trade bar shows different values from when you're putting it together and then when you submit it. Which is to say, if it's saying a trade is valued somewhat in the other team's favor when you're putting the trade together, once you've submitted it to them it might then show that it's slightly in your favor.

I think it was a trade with jsid that I did, that he sent me a trade and the bar was set at whatever it was. I was curious to see where the bar would be if I sent the exact same trade, the swing was fairly massive. I can't remember to who it favored, but I don't think the trade weights are correct, unless there is a difference to who is sending/receiving a trade?

I'd suspect the trade bar uses your individual weightings rather than any nominally "true" weightings.

You favour an attribute pretty high, then you'll see a different bar than someone who doesn't favour that attribute.

The trade bar is a work in progress, and went through a big overhaul a month? ago and was updated again last week for older players.

A recent trade that I made looked exactly the opposite from my side as did from the point of view of the other owner. He said that it favored me, but I saw that it favored him by the same amount.

If you hover over MY TEAM you will see a tab that says PLAYER WEIGHTS, this is where you can edit what attributes matter to you with individual positions, that can influence the trade bar, how you value a player Vs how another owner sees them.