That point was in reference to just transparency of data. Right now, you can’t call up NYSE and ask “hey, can you tell me the pattern for when people buy AAPL? And in particular, Warren Buffet?”.

On the blockchain you can do exactly that (but instead of Warren Buffet it’s wallet XXXX)

You bring up a great point though with speed still being an issue as far as your physical connections go. Luckily, since blocks have to be verified, miners have to be paid for verifications, and verifications take time, you have to pay for speed in a very upfront way. This greatly increases the transaction cost and would in theory make in unprofitable for someone to exploit it.

For example, on the ETH blockchain, you pay gas for each transaction. The more gas you pay, the faster your block is executed.

So again, the bar for speed is now for everyone, (whoever pays more gas) and not just whoever built a fiber optic cable network to the closest exchange. It would be insane to build special cables to every blockchain node operator on the planet.

This was such a good question I want to update the article now!