There are a handful of private companies working on new/not well researched approaches to cracking fusion using private capital while Government projects like National Ignition Labs and ITER suck most of the public funding to work on mainstream methods.
There are two companies of note,
1) General Fusion (funded in part by Bezos) working on something called magnetised target fusion
Here's how it works: first, magnetic fields are used to confine a superheated plasma of volatile deuterium and tritium isotopes. This plasma is then injected into a sphere, where it's briefly contained in a vortex of liquid metal. Next, pistons converging towards the centre of the sphere simultaneously strike an anvil at the end of their cylinder, sending a shock wave into the plasma. This burst of energy causes the plasma to compress and the deuterium-tritium fuel to ignite – producing, in theory, a tremendous burst of energy.
2)Tri Alpha (Paul Allen) using a reactor tech called called a “field-reversed configuration.” This type of device has more in common with Iter's tokamak-style reactor than General Fusion’s machine: it uses magnetic confinement and heat, rather than compression, to induce fusion, and it produces energy continuously, instead of in bursts. The advantage of a field-reversed configuration over a tokamak is that its engineering is much simpler. But from a physics perspective, the technology is far less well-developed.
Conclusion is that both these companies are following long shot techs and it's challenging for them to raise capital since they'll take a long long time to give VC an exit, if ever. But if they work, then their investors hit jackpot.