Bitcoin blocks and the next block being built

How do I read this chart?

Every bar is one Bitcoin block, found about every ten minutes. Pick a number at the top and the bars show it for each block. The bar on the far right is the block being built right now. It is a guess, drawn dotted. Everything to its left has been found and will never change.

What is the block being built?

Payments wait in a line until a miner includes them. The ones that pay the highest fees go first, and one block only holds so much, so the guess takes the best-paying payments up to one block of space. That is what a miner would take if a block were found this second. It is not the whole line, which is usually many blocks long.

How good is the guess?

When a block is found, its bar locks to the real figure and a thin line marks what the guess said. The line sits above the bar when the guess was too high, and below when it was too low. New payments keep arriving and miners do not always take the same ones, so some miss is normal. The card above gives the typical miss for the number you picked.

Why are some numbers only for big payments?

Working out how old the coins in a payment are, or whether they were bought lower or higher, means looking up where each coin came from. Maketo does that only for payments of 1 Bitcoin or more, so those numbers are a floor for the whole block, not the whole. For the other numbers, such as old-coin activity for the whole block, the answer is known only after the block is found, so the building bar stays empty.

Why do I need to sign in for the live bar?

The mined blocks are open to everyone. The block being built changes every few seconds, so its live bar is for signed-in readers. Signing in uses an email code and takes a moment.

Does this say where the price is going?

No. It counts payments, fees and coins moved. Busy blocks and quiet blocks are both normal, and neither one tells you where the price goes next.