In a large soup pot, heat the olive oil. Add the shallot and garlic and cook over high heat, stirring, until softened, about 3 minutes.
Add the wine and boil until reduced by half, about 3 minutes.
Add the stock, clam juice, tomatoes, thyme, bay leaf and hot sauce and season with salt and pepper. Bring to a boil over high heat and cook until slightly reduced, about 10 minutes.
Add the clams, cover and cook just until most of them open, about 5 minutes.
Add the snapper and shrimp, cover and simmer until they are cooked through and the remaining clams have opened, 2 to 3 minutes.
Using a slotted spoon, transfer the seafood to 4 bowls.
Add the butter and parsley and cook over moderate heat for 1 minute, swirling the pan.
Spoon the broth over the seafood and serve with sourdough toast.