IMHO, it's better for Apple to be a foundary customer than to run an internal foundary.

As a customer, if TSMC falters, they can switch to Samsung or Intel (if Intel foundary materializes).

As a vertical foundary, it's very hard to switch if it falters. AMD managed to spin out their foundry which was becoming non-competitive and switch to TSMC, Intel has a lost decade because of the pipeline bubble caused when the Intel 10nm foundary arrived late and with poor yields.

Apple has a very hard time selling to business, and I think would not be able to credibly provide foundry services to others, so it only works if they can keep it on the leading edge.

Never say never but I suspect they are quite happy with the current setup. Apple makes premium devices. Everybody needs a mix of chips but their needs skew toward the newest node. They can instead pay TSMC a bunch of money to reserve capacity on the next node, funding the construction of the facilities, in exchange for a spot at the front of the queue. Then, when the node after that shows up, they can move along, and TSMC can continue using it for lower-margin companies.

There’s no need for Apple to buy a foundry when they can afford to purchase virtually all of TSMC’s capacity for any new chip process.

>At what point will Apple try to build/buy their own foundry?

Likely never. As long as you understand how foundry works, economy of scale, long tail of older nodes, capacity planning and amortisation of R&D.

i.e Unless Apple is happy to Fab for their Android competitors and their Android Competitors are also somehow happy to buy from them the likely hood of that happening is practically zero.

Apple is exactly like the CCP; It has a 10, 25, 50 year roadmap that it secretly works on.

Recall that famous article about the "largest hedge fund nobody has heard about" -- Apples hedgies that were a couple of people in Reno Nevada?

Surely they have been looking at the math forever - I wouldnt be surprised if they have already pulled the trigger on something.

However, they are masters of supply chain - and were investing in companies that are inputs to their supply chain, and rig the system for their own margins.

They would buy up a companies capacity for a component, and invest in them, and basically own that node in the chain.

With Ruthless brilliance.

> At what point will Apple try to build/buy their own foundry?

As soon as they are tired of having money.

It isn’t just the cost of building Fabs, literally their entire supply chain is based on being Fabless, and changing that is ridiculously expensive. They have some amazingly skilled chip designers inhouse, but even so many aspects of the actual manufacturing side of the design process were not done at Apple, although they exert an outsized influence.