That they “always sell their best players”.
The Seagulls are going into a tough-looking season and Bloom believes they have their strongest-ever squad.
They have pieced that group of players together despite the sales of Jan Paul van Hecke, Carlos Baleba and Danny Welbeck, while James Milner and Joel Veltman declined contract offers.
But they have also refreshed and strengthened in many areas, including a flurry of activity in the final fortnight of the transfer window.
Albion are known for letting players go to big clubs for huge fees.
Not only is it part of their financial model but it is also a factor in persuading such players to join them in the first place.
But the idea that they always sell their best players as soon as a richer club comes calling is a false one and they have underlined that in the last two summers.
There was never any chance of them allowing Baleba to go last summer as Manchester United moved in.
And they repelled offers and strong interest from Liverpool in Yankuba Minteh more recently.
Albion are also understood to have rejected offers for Amario Cozier-Duberry.
Bloom told The Argus: “Everything about players can be complicated.
“We know that players, when they perform really well, they will be attractive to other clubs.
“If the timing is right, and if the price is right, and if the player wants to leave, then the player will leave.
“But those things all have to happen.
“I don’t want to talk individual situations, but as I said for a player to be sold, you need the right set of circumstances.”
While it would appear highly possible Minteh will go for big money if he recovers from injury and starts to shine again, Albion judged him a player they were not yet ready to let go.