Entertaining the SEC / Brainstorming

A key issue with getting a spot ETF is that spot pricing for BTC may be easily manipulated (since exchanges aren't perceived as robustly regulated)

What is a fair way to quote the price of the fair exchange rate of BTC-USD? What best practices should exchanges adopt in the public interest?

Here's some of my concerns

• 1. You can't set a minimum order size lower than a satoshi, so limiting pricing to huge lots like 100 BTC as happens in Stocks and ETFs is out.
• 2. It shouldn't be considerably more manipulable in periods of lower volume, there should be some period over which it's not feasible for a small group to control the headline number by spoofing the orderbook.

... so maybe some sort of order-book-median running average, weighted by on-chain volume, where periods of "real-exchange" carry more weight than "virtual-exchange" - volume, since that type of trade may not be subject to appropriate fees?

I don't know, what do you guys think?

• Did I miss any pricing concerns?
• Are there better solutions?
• Have exchanges begun adopting any such practices?