Used to own it 10 years ago. Sold it WAY too early and missed out on many multiples of return.
Unless something changed with it, it is based on percentage royalties from actual production from a specific field in Prudhoe Bay Alaska. 10 years ago the thoughts were that the contractual operating costs would escalate per the Trust documents such that it would be worthless (costs would exceed per barrel revenue) over the next 10 years or so. Significantly higher oil prices have changed the calculation of intrinsic value. But eventually the production at Prudhoe bay will taper off (field depletion) or the contractual costs will exceed the per barrel revenue (per barrel revenue is tied to West Texas Intermediate crude).
Money is the Root of All Good.