There are differents families of equipment, all of them have their own theme. The more items of the same theme the Stonks is equipped with, the rarer it is. The background color will change according to the rarity.
For example, there is an Ergo hat, an Ergo clothing and an Ergo accessory, there is a Bitcoin hat, a Bitcoin clothing and a Bitcoin accessory…etc.
The generation is random. All generated parts have the same % chance of being drawn.
Try the rarity simulator :
The exclusives stonks are not randomly generated. They're handmade and statistically rarer than "rare" stonks but less rare than "legendary" ones. But the unique design of exclusive stonks can push them beyond the hype for a legendary one.
You'll also find a few rare and common stonks that have been modified when some exclusive stonks were released. They're still considered rare or common, but... probably more coveted!
To avoid fake Ergo Stonks, we highly recommend that you use SkyHarbor. This is a safe place with a user-friendly interface.