Bitcoin is digital money that no company or government runs. Thousands of computers keep one shared record of who owns which coins, new coins arrive on a fixed schedule that stops just under 21 million, and anyone can send it to anyone without a bank in the middle. It was announced by someone calling themselves Satoshi Nakamoto on Oct 31, 2008, and the network has run since Jan 3, 2009.
Updated · every number has a source at the bottom
PM Countdown is not affiliated with any exchange or prediction market, and nothing here is advice to buy or sell. How we source and check numbers · Responsible gambling
The short version
Bitcoin in one minute three ideas, nothing else
Everything else on this page is detail on these three.
01
One shared record
Thousands of computers keep the same ledger of who owns which coins. New pages of it, called blocks, are added about every 10 minutes, each one chained to the last, which is where the word blockchain comes from.
02
A fixed supply
No one can print more. New coins come only as a reward for adding blocks, the reward halves on a schedule, and the total stops just under 21 million. About 20.09 million exist today.
03
No one in charge
The rules live in open-source software anyone can run and check. There is no company to call, which also means no one can reverse a payment you sent by mistake.
How it moves
How a payment works from your wallet to a block
- A wallet holds keys, not coins. The coins live on the shared record. Your wallet holds the secret key that proves you can spend them. Lose the key and the coins are stuck for good.
- You sign and broadcast. Sending bitcoin means signing a message with that key and passing it to the network, with a fee attached for the miners.
- A miner puts it in a block. Miners pick waiting payments, usually the ones paying the highest fee first, and pack them into the next block.
- Blocks pile on top. Each new block makes the ones under it harder to rewrite, so a payment gets safer with every block after it. Large payments usually wait for several.
Every payment is public. You can look up any address and its history; the wallet tracker does exactly that for the 100 largest.
Proof of work
Mining and the reward the work behind each block
The whitepaper borrows the idea from Hashcash: to add a block, a miner has to find a number that makes the block’s fingerprint fall under a target, and the only way to find it is to guess, billions of times a second. That guessing is the work, and it is what makes rewriting old blocks too expensive to try.
Every 2,016 blocks, about two weeks, the network resets how hard the target is, so blocks keep coming about every 10 minutes no matter how many machines join. Since Apr 19, 2024 the reward for a block is 3.125 BTC, plus the fees in it.
Bitcoin mining calculator
Pick a machine and a power price, and see what one coin costs to mine, all in.
Open the mining calculator21 million
When the reward halves once every 210,000 blocks
The halving is the one scheduled change to how many new coins appear. It happens at a block height, so the date can only be estimated.
| Block | When (PT) | Reward after |
|---|---|---|
| 0, the start | Jan 3, 2009 | 50 BTC |
| 210,000 | Nov 28, 2012 | 25 BTC |
| 420,000 | Jul 9, 2016 | 12.5 BTC |
| 630,000 | May 11, 2020 | 6.25 BTC |
| 840,000 | Apr 19, 2024, 5:09 PM | 3.125 BTC |
| 1,050,000 | Expected around April 2028 | 1.5625 BTC |
The next halving, counted in blocks · Live Bitcoin block globe
Who holds it
Who holds the most the exchanges, the funds and Satoshi
Bitcoin wallet tracker
The 100 largest addresses, who holds them where a source says so, and when each last sent coins. On Oct 6, 2026 the largest, a Binance cold wallet, held 248,598 BTC.
Open the wallet trackerSatoshi’s coins
About 1.096 million BTC across some 22,000 addresses, by Arkham’s count, untouched since 2010. Two markets trade on whether any of it moves.
Will Satoshi’s coins move?Ways in
How people trade it from holding to 15-minute windows
| What you hold | Most you can lose | Where we cover it | |
|---|---|---|---|
| Buy the coin | Bitcoin itself, on an exchange or in your own wallet | What you paid | Wallet tracker |
| Spot funds | Shares of a fund that holds bitcoin; US listings approved on Jan 10, 2024 | What you paid | Coming soon |
| Perpetual futures | A leveraged position with no expiry, priced off the coin | Your margin, and more if the close slips | Bitcoin perpetuals |
| 15-minute up or down | A contract that pays $1 if the window closes the way you picked | What you paid plus the fee | 15-minute desk |
| Hourly price strikes | A contract on where Bitcoin is at the top of the hour | What you paid plus the fee | Hourly desk |
| Event markets | Yes or no on a Bitcoin event, such as Satoshi’s coins moving | What you paid plus the fee | Satoshi’s coins |
Short windows restart every 15 minutes, which makes it easy to keep going after a loss. Set a limit before you start. How to set a loss limit
Timeline
The dates that matter from a mailing list to Wall Street
All times Pacific.
The paper. Satoshi Nakamoto posts “Bitcoin P2P e-cash paper” to a cryptography mailing list at 11:10 AM PT.
The first block. Mined at 10:15 AM PT, carrying a line from that day’s Times of London about a second bank bailout.
Block 1. The chain keeps going at 6:54 PM PT, Jan 9 in UTC.
Two pizzas. Laszlo Hanyecz reports trading 10,000 bitcoins for pizza, the famous early purchase now marked as Bitcoin Pizza Day.
Satoshi’s last forum post. Notes on a software release. Satoshi drops out of public view soon after.
The first halving. The block reward falls from 50 to 25 BTC.
Spot funds in the US. The SEC approves the listing of spot bitcoin exchange-traded products.
The fourth halving. Block 840,000 at 5:09 PM PT; the reward drops to 3.125 BTC.
The next halving. Block 1,050,000; the reward drops to 1.5625 BTC.
Questions
What people ask most and the plain answers
Who created Bitcoin?
Someone using the name Satoshi Nakamoto. The paper was announced on Oct 31, 2008, the network started on Jan 3, 2009, and no one has proven who Satoshi is. Satoshi’s last post on the Bitcoin forum was on Dec 12, 2010.
Is there really a limit of 21 million?
Yes. New coins come only as the reward for each block, and that reward halves every 210,000 blocks. Add it up and the total stops just under 21 million, around the year 2140. About 20.09 million had been mined by Oct 6, 2026.
What is a satoshi?
The smallest unit of bitcoin: one hundred-millionth of a coin, or 0.00000001 BTC. Prices and fees are often quoted in sats.
How long does a Bitcoin payment take?
A new block lands about every 10 minutes, and a payment counts as confirmed once it is in a block. Each block after it makes the payment harder to undo, so large payments usually wait for several.
Can I trade Bitcoin over 15 minutes or an hour?
Yes. Prediction markets list contracts that ask whether Bitcoin will be up or down at the end of a 15-minute window, or above a price at the top of the hour. Each costs between 1¢ and 99¢ and pays $1 if it is right. You can lose what you paid. Our 15-minute desk shows one live.
Does PM Countdown sell bitcoin?
No. We don’t sell, hold or custody coins, and we aren’t affiliated with any exchange or prediction market. We post our calls in public and grade them.
Get our Bitcoin calls in one email a day. Misses included, at a set time, nothing else.
Sources
Where this comes from checked Oct 6, 2026
- Bitcoin: A Peer-to-Peer Electronic Cash System (the whitepaper)
- Satoshi’s announcement on the cryptography mailing list, Oct 31, 2008
- The genesis block, mempool.space
- Controlled supply and the halving schedule, Bitcoin Wiki
- Difficulty, Bitcoin Wiki
- Block 840,000, the April 2024 halving, mempool.space
- Coins mined so far, blockchain.info (read Oct 6, 2026)
- SEC Chair statement on spot bitcoin exchange-traded products, Jan 10, 2024
- Bitcoin Pizza Day forum thread, May 22, 2010
- Satoshi’s last forum post, Satoshi Nakamoto Institute
Rounded on purpose: “about 20.09 million mined” because sources read a few blocks apart give slightly different totals. The April 2028 halving date is an estimate from the current block height at 10 minutes a block.
Keep going