How many wand makers are there in the Harry Potter universe? Is there only a select few people that can make wands or is there like a wand company?
There are a few known ones:
- The Ollivander family
- Gregorovitch, who made Viktor Krum's wand
- Arturo Cephalopos, mentioned on Pottermore
- Antioch Peverell, original owner of the Elder Wand, was believed by Dumbledore to have made it himself; there's no confirmation of this, however
- A sign for "Jimmy Kiddell's Wonderful Wands" is briefly glimpsed in Diagon Alley in the Philosopher's Stone movie; whether you consider Mr. Kiddell to be canon is largely up to you
- As I remark in an answer to a different question, an American wandmaker named Violetta Beauvais is referenced in a newspaper headline in background details for the 2016 film Fantastic Beasts and Where to Find Them. As Valorum notes, she also appears on Pottermore, making her a fully-canon character
We know that there are more (the Pottermore entry on wand woods frequently uses "wandmakers" as a collective noun), but we don't know how many; the Pottermore entry on Mr. Ollivander called wandcraft a "mysterious profession":
The family of Ollivander has long been associated with the mysterious profession of wandcraft.
So it seems likely that it's a fairly rare trade
In addition to Jason Baker's fine answer, we also have this information from Pottermore in relation to the new Fantastic Beasts film. In brief, there are four main makers of American wands.
Shikoba Wolfe, who was of Choctaw descent, was primarily famous for intricately carved wands containing Thunderbird tail feathers (the Thunderbird is a magical American bird closely related to the phoenix). Wolfe wands were generally held to be extremely powerful, though difficult to master. They were particularly prized by Transfigurers.
Johannes Jonker, a Muggle-born wizard whose No-Maj father was an accomplished cabinet maker, turned himself into an accomplished wandmaker. His wands were highly sought after and instantly recognisable, as they were usually inlaid with mother-of-pearl. After experimenting with many cores, Jonker’s preferred magical material was hair of the Wampus cat.
Thiago Quintana caused ripples through the magical world when his sleek and usually lengthy wands began entering the market, each encasing a single translucent spine from the back of the White River Monsters of Arkansas and producing spells of force and elegance. Fears about over-fishing of the monsters were assuaged when it was proven that Quintana alone knew the secret of luring them, a secret he guarded jealously until his death, at which point wands containing White River Monster spines ceased production.
Violetta Beauvais, the famous wandmaker of New Orleans, refused for many years to divulge the secret core of her wands, which were always made of swamp mayhaw wood. Eventually it was discovered that they contained hair of the rougarou, the dangerous dog-headed monster that prowled Louisiana swamps. It was often said of Beauvais wands that they took to Dark magic like vampires to blood, yet many an American wizarding hero of the 1920s went into battle armed only with a Beauvais wand, and President Picquery herself was known to possess one.
Interestingly, from what we know about their unique manufacturing styles, Graves seems to be sporting a Jonkers wand.