How to scale Bitcoin (without changing a thing)

Why Bitcoin banks need to prove their solvency. By this I mean the Finneyan view of Bitcoin in which Bitcoin banks emerge and issue notes against deposited Bitcoin. If you look carefully, a proto version of this system is in place today. However, for cherished assurances like scarcity to be upheld, exchanges and custodians need to start making routine attestations that their reserves match their liabilities.