The weekly Bitcoin brief, issue #1

Six short cards you can read in a few minutes. Plus the week in Bitcoin.

Cold Hard Sats

Cold Hard Sats

— 12 min read
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Week of Oct 12–18, 2026.

Welcome to the first Bitcoin brief from Cold Hard Sats! A quick word on the name. A sat, short for satoshi, is the smallest unit of bitcoin: one hundred-millionth of a coin[31], named after bitcoin's pseudonymous creator, Satoshi Nakamoto. The name is a play on “cold hard cash,” money that's truly yours. The “cold” is also a nod to cold storage: keeping your bitcoin keys offline, on a device only you control.

Thanks for your interest. Someone who tried the site told us it felt like a lot to digest. Fair. So before the charts and news, let's start with the basics.

In this issue:

●  Start here●  FUD Corner
●  Price vs. trend●  Security
●  What if?●  Technical
●  Network●  Videos
●  News●  Ask us
●  Feature 

New to bitcoin? Start here

Bitcoin, the simple version is six short cards you can read in a few minutes:

  1. What bitcoin is
  2. Why some people hold it
  3. The one rule (your recovery words)
  4. Buying bitcoin
  5. Start small
  6. Check your backup works

No jargon without an explanation. Each card stays short and links out to a deeper page when you want more: how to buy, hardware wallets, multisig, the glossary.

Read Bitcoin, the simple version

Already know the basics? Send it to someone who doesn't.

Watch the mining of a Bitcoin block

Watch the mining of a Bitcoin block
Click to watch: Watch the mining of a Bitcoin block (45 seconds)

Every 10 minutes or so, a new block is added to Bitcoin. Here's how one comes together, in 45 seconds.

Watch the mining of a Bitcoin block

Price vs. trend

📈

$81,269, about 52% below trend. Far below trend by that model (9th percentile historically).

Bitcoin vs. the Bitcoin Power Law model (Giovanni Santostasi), Oct 17, 2026
Model: Giovanni Santostasi, Bitcoin Power Law[1]. Price data: Coin Metrics Community[2]. Chart: Cold Hard Sats.

Bitcoin briefly dipped below $80,000 on Thursday, Oct 15, the day after hotter-than-expected U.S. inflation data, then buyers pushed it back to about $82,000[3]. Santostasi's model puts the Oct 17 trend near $168,900, so price is at 0.48x trend. Price has been this far or further below trend on about 9% of days since July 2010[2][1].*

See the power law chart

📊

What if? $1,000 to start, $100 a week
Picture $1,000 put into bitcoin at this issue's price of $81,269 (Coin Metrics close, Oct 17, 2026)[2]. That buys about 0.0123 BTC.†† Then picture $100 more each week at that week's Coin Metrics close. Each issue updates the total put in, what it would be worth and the % change. This is a hypothetical illustration, not advice or a recommendation: nobody is buying, and it leaves out fees, spreads and taxes. Past performance doesn't predict future results.

 
This issue (hypothetical)
Total put in$1,000
BTC0.0123
Would be worth$1,000
Change0.0%

Network

  • Block height: 972,036[4]
  • Next halving: block 1,050,000, 77,964 blocks away. Around April 11, 2028 (~541 days).†
  • Block subsidy: 3.125 BTC[5]
  • Hashrate: about 1,020 EH/s, mempool.space's current estimate[6]
  • Difficulty: about 140.6 trillion. Next adjustment in 1,692 blocks, estimated at −0.3%[7]
  • Supply issued: about 20,100,116 BTC, roughly 95.7% of a total that is capped at just under 21 million.‡

See the supply schedule

This week in Bitcoin

  • Fees are near the floor: 1–3 sat/vB on Sunday afternoon[8]. A low-cost time to withdraw from an exchange, or to combine many small amounts your wallet controls into one (UTXO consolidation).
  • Schwab opens bitcoin buying to all eligible clients. Charles Schwab made Schwab Crypto available to all eligible retail clients on Oct 16, with bitcoin and ether trading at 0.75% per trade[9]. Schwab's bank is the custodian, with Paxos as sub-custodian, so Schwab and Paxos hold the keys[10]. Earlier in the week, Standard Chartered launched BTC and ETH trading for Professional Investor clients in the UAE, with the bank holding custody[11], and Bulgaria's Fibank added Bitpanda's crypto services to its app[12].
  • MSCI's new rules put Strategy on notice. MSCI adopted rules that make companies that mainly hold investments ineligible for its global indexes. The affected companies will be named Nov 11, and changes take effect after the Nov 30 close[13][14]. Index funds would sell the shares, not bitcoin[13].
  • Binance is closing its mining pool. Binance Pool shuts on Nov 10. Its hashrate has fallen about 65% since December, and the three largest pools now account for about 64% of the network's hashrate[15].
  • The CFTC opened comments on crypto trading rules. The advance notice covers regulated trading venues; comments close Dec 14, 2026[16]. Nothing changes if you hold your own keys.
  • Spot bitcoin ETF flows, Oct 12–16: −$228.4M net[17].§

Feature: bitcoin's first price tag

On Oct 12, 2009, Martti Malmi sent 5,050 BTC to a buyer called NewLibertyStandard for $5.02, paid by PayPal. It's the first known sale of bitcoin for dollars[18][19]. A week earlier, NewLibertyStandard had published one of the first exchange rates: 1,309.03 BTC to $1[19].

Seven months later, on May 22, 2010, Laszlo Hanyecz reported trading 10,000 BTC for two pizzas, a day now marked as Bitcoin Pizza Day[20].

For perspective: at the Oct 17 price of $81,269[2], those 5,050 BTC would be worth about $410 million.‖

Explore the Bitcoin timeline

FUD Corner: "Quantum computers will steal your bitcoin"

🔍

The claim: Experts quoted by CoinDesk say a future quantum computer could expose the keys behind about 6.4 million BTC, including roughly 1.1 million attributed to Satoshi[21].

The facts: No existing quantum computer can do this, and experts disagree on when one might. Standards work and developer debate are underway[21]. It's a long-term engineering problem with warning time, not an emergency. Good habit anyway: use a fresh receiving address for every payment.

Read our take on quantum fears

Security Corner

The Ledger implant, by the numbers. Galaxy Research counts roughly $91 million taken from 474 addresses, including 213 BTC from 279 bitcoin addresses, and calls its count a floor[22]. Ledger hasn't confirmed a total[23]. The implant reads the 24 words off the screen during setup, and Ledger's Genuine Check still passes on a tampered unit. Some victim addresses date to 2021, consistent with existing recovery words being restored onto tampered devices[22].

Ledger's response. Ledger says its chip, operating system and servers weren't compromised. It asked resellers in Southeast Asia and Hong Kong to suspend sales and now requires stores to keep devices off shelves[24]. If you bought from CryptoBilis and haven't set the device up, don't. If you did, set up a new device bought direct, with new recovery words, and move your bitcoin to a receiving address that new device generates[22][24].

Scams riding the news. Fake Ledger update pages are stealing recovery words[25][26]. Security researcher Taylor Monahan said the newest Ledger loss reports she reviewed came from scams aimed at worried owners (fake apps, phishing sites, misleading ads, scam calls), not from the implant[23]. Update only in the official Ledger Wallet app. No real update asks for your words.

🔒

One thing to do this week: Check where your hardware wallet came from. Buy direct from the maker. If a device arrives already set up, or with recovery words already printed, treat it as compromised[22].

How to choose a hardware wallet

Technical Corner: the difficulty adjustment

Bitcoin targets one block every 10 minutes. Every 2,016 blocks, difficulty resets: harder if blocks came fast, easier if slow, by at most a factor of 4[27]. This period averages about 600 seconds per block, and mempool.space estimates the next change at −0.3%, after +5.9% last time[7]. That steadiness is why the halving date can be estimated at all.

See the live difficulty estimate

Cold Hard Sats Originals

A lone walker on a cracked desert road at sunset, with "$51.55" on screen
Click to watch: Saving in shrinking money (17 seconds)

Saving in shrinking money. By September 2026, $100 saved in September 2000 buys only what $51.55 bought back then, measured by the U.S. consumer price index (CPI-U)[28]. Saving in dollars is a long walk downhill. Bitcoin works differently: its supply is capped at just under 21 million[29].

Watch "Saving in shrinking money" (17 seconds)

Everywhere but nowhere: a bag of gold stopped at airport security
Click to watch: Everywhere but nowhere (19 seconds)

Everywhere but nowhere. A bag of gold gets stopped at airport security while a traveler who memorized 12 words walks straight through. (The words shown are illustrative; always keep a durable backup.)[30]

Watch "Everywhere but nowhere" (19 seconds)

Who holds your keys?
Click to watch: Who holds your keys? (12 seconds)

Who holds your keys? Banks hold everyone's money, and everyone's keys. Not his: banks hold their keys, you hold yours.[30]

Watch "Who holds your keys?" (12 seconds)

This week's video picks

Picked from the latest uploads on the Cold Hard Sats videos page, Oct 12–18. Titles as shown there.

Not ours, and not a recommendation: the videos page also collects five Coinbase ads (2023–2026) that use worries about prices and saving to market an exchange. We show them as examples of money marketing. Cold Hard Sats has no affiliation with Coinbase and doesn't endorse it[30]. Why we show them

See all the latest videos

Ask us anything

❓

Do I have to buy a whole bitcoin? No. Bitcoin divides into 100,000,000 units called satoshis, or sats[31]. Look up sats in the glossary

Got a question? Reply to this email. We read every reply.

Ready for more?

Take the free course

That's issue #1. Keep your keys close and your recovery words offline. See you next week.

— Cold Hard Sats
coldhardsats.com

Notes

* Model: price = 10⁻¹⁷ × (days since Jan 3, 2009)^5.83; Oct 17 is day 6,496[1]. The verdict ranks the Oct 17 distance from trend among all days since July 18, 2010 (Coin Metrics daily prices through Oct 17, 2026, accessed Oct 18, 2026, 2:35 PM ET[2]). The power law models past data. It is not a prediction; price can stay far from trend for years, and the relationship could break.

† 77,964 blocks × 599.5 s average block time in the current difficulty period[7] ÷ 86,400 s/day. Rough, since block times vary. Network data (block height, hashrate, difficulty, fees) from mempool.space, Oct 18, 2026, 2:35 PM ET.

‡ From the subsidy schedule[5]: 19,687,500 BTC for blocks 0–839,999, plus 3.125 BTC × 132,037 blocks since (840,000–972,036). An upper bound, since it counts lost or unspendable coins.

§ Daily: Oct 12 −$65.4M, Oct 13 +$175.7M, Oct 14 −$261.4M, Oct 15 +$5.1M, Oct 16 −$82.4M (Farside[17], accessed Oct 18, 2026, 2:36 PM ET). U.S. markets were closed Oct 17–18.

†† Illustration method (hypothetical; excludes fees, spreads and taxes): issue #1 assumes $1,000 of bitcoin bought at the Coin Metrics Community daily PriceUSD close for Oct 17, 2026, $81,268.94[2]: 0.0123048 BTC (about 1,230,482 sats), accessed Oct 18, 2026, 2:35 PM ET. Each later weekly issue assumes $100 more at that issue's Coin Metrics close. BTC held is the sum of all buys; value = BTC held × the current Coin Metrics close; % change = (value ÷ total invested − 1) × 100.

‖ 5,050 × $81,268.94 = $410,408,163, using the Oct 17 Coin Metrics price[2].

¶ Titles, channels and dates as shown on coldhardsats.com/videos, feed refreshed Oct 18, 2026, 2:04 PM ET.

$51.55 = $100 × 173.7 ÷ 336.940 (CPI-U, September in both years, not seasonally adjusted), checked against the BLS API on Oct 17, 2026[28].

Sources

  1. Giovanni Santostasi, "BTC Trolololo model revisited (still valid today) is really a Power Law in disguise," Medium, January 2024. https://giovannisantostasi.medium.com/btc-trolololo-model-revisited-still-valid-today-is-really-a-power-law-in-disguise-da11b58cf5de
  2. Coin Metrics, "Community API: BTC PriceUSD, daily," Jul 18, 2010 – Oct 17, 2026, accessed Oct 18, 2026, 2:35 PM ET. https://community-api.coinmetrics.io/v4/timeseries/asset-metrics?assets=btc&metrics=PriceUSD&frequency=1d
  3. Shaurya Malwa, CoinDesk, "Bitcoin buyers snap up a brief drop below $80,000 as Asian stocks rebound," Oct 16, 2026. https://www.coindesk.com/markets/2026/10/16/bitcoin-buyers-snap-up-a-brief-drop-below-usd80-000-as-asian-stocks-rebound
  4. mempool.space, "Block tip height API," accessed Oct 18, 2026, 2:35 PM ET. https://mempool.space/api/blocks/tip/height
  5. Bitcoin Core, "validation.cpp (GetBlockSubsidy)," GitHub. https://github.com/bitcoin/bitcoin/blob/master/src/validation.cpp
  6. mempool.space, "Mining hashrate API (1 week)," accessed Oct 18, 2026, 2:35 PM ET. https://mempool.space/api/v1/mining/hashrate/1w
  7. mempool.space, "Difficulty adjustment API," accessed Oct 18, 2026, 2:35 PM ET. https://mempool.space/api/v1/difficulty-adjustment
  8. mempool.space, "Recommended fees API," accessed Oct 18, 2026, 2:35 PM ET. https://mempool.space/api/v1/fees/recommended
  9. Whitney Nyantune, Coin Edition, "Charles Schwab Expands Bitcoin Trading, Plans Three New Crypto Listings," Oct 16, 2026 (quotes Schwab's Oct 16 post on X). https://coinedition.com/crypto-live-news/charles-schwab-expands-bitcoin-trading-plans-three-new/
  10. Charles Schwab, "Charles Schwab Announces Details of Spot Crypto Trading Launch," press release, Apr 16, 2026. https://pressroom.aboutschwab.com/press-releases/press-release/2026/Charles-Schwab-Announces-Details-of-Spot-Crypto-Trading-Launch/default.aspx
  11. Standard Chartered, press release, Oct 14, 2026. https://www.sc.com/en/press-release/standard-chartered-unveils-first-of-its-kind-cryptocurrency-trading-solution-for-affluent-clients/
  12. Fibank / PR Newswire, Oct 12, 2026. https://www.prnewswire.com/news-releases/fibank-and-bitpanda-forge-strategic-partnership-to-launch-integrated-crypto-asset-access-via-my-fibank-mobile-app-302905615.html
  13. Omkar Godbole, CoinDesk, "MSCI makes it official, and bitcoin (BTC) treasury firms Strategy, Metaplanet are on notice," Oct 16, 2026. https://www.coindesk.com/markets/2026/10/16/msci-approves-rules-that-could-eject-strategy-metaplanet-from-equity-indexes
  14. MSCI, "MSCI announces results of the consultation on the eligibility of non-operating companies in the MSCI Global Investable Market Indexes," Oct 15, 2026. https://app2.msci.com/webapp/index_ann/DocGet?lang=en&pub_key=aq0wbkjxPgo%3D
  15. Shaurya Malwa, CoinDesk, "Bitcoin mining pool once handling 2.3% of network shuts after hashrate falls 65%," Oct 15, 2026. https://www.coindesk.com/markets/2026/10/15/bitcoin-mining-pool-once-handling-2-3-of-network-shuts-after-hashrate-falls-65
  16. Commodity Futures Trading Commission, "Regulation Crypto Asset Transactions and Regulation Crypto Asset Markets" (ANPRM), Federal Register, Oct 13, 2026. https://www.federalregister.gov/documents/2026/10/13/2026-20888/regulation-crypto-asset-transactions-and-regulation-crypto-asset-markets
  17. Farside Investors, "Bitcoin ETF Flow – All Data," accessed Oct 18, 2026, 2:36 PM ET. https://farside.co.uk/btc/
  18. Reuters Staff, "Factbox: Ten years of bitcoin," Reuters, Oct 31, 2018. https://www.reuters.com/article/technology/factbox-ten-years-of-bitcoin-idUSKCN1N50GE/
  19. Bitcoin Institute, "First Bitcoin sale for fiat — Martti Malmi sells 5,050 BTC for $5.02," updated Oct 12, 2026. https://bitcoin-institute.pages.dev/entries/aftermath/2009-10-12-martti-malmi-first-btc-sale/
  20. Laszlo Hanyecz, "Pizza for bitcoins?", BitcoinTalk topic 137. https://bitcointalk.org/index.php?topic=137.0
  21. CoinDesk, "Quantum Alliance forms to defend 6.4 million vulnerable bitcoin against future threats," Oct 16, 2026. https://www.coindesk.com/tech/2026/10/16/experts-agree-quantum-computers-could-put-satoshi-s-bitcoin-at-risk-but-not-on-what-s-next
  22. Alex Thorn, Galaxy Research, "Not Your Reseller, Not Your Coins," Oct 16, 2026. https://www.galaxy.com/insights/research/ledger-cryptobilis-wallet-implant-theft
  23. Simon Yoon, TokenPost, "Taylor Monahan Says New Ledger Loss Reports She Reviewed Involved Scams," Oct 17, 2026. https://www.tokenpost.com/news/technology/33770
  24. Ledger, "Ledger's Response to the Hardware Implant Attack," Oct 15, 2026. https://www.ledger.com/blog-response-hardware-implant-attack
  25. SlowMist (@SlowMist_Team), post on X, Oct 16, 2026. https://x.com/SlowMist_Team/status/2110988183039332417
  26. The Crypto Times, "Fake Ledger firmware update scam exploits CryptoBilis hack, SlowMist warns," Oct 16, 2026. https://www.cryptotimes.io/2026/10/16/fake-ledger-firmware-update-scam-exploits-cryptobilis-hack-slowmist-warns/
  27. Bitcoin Core, "pow.cpp," GitHub. https://github.com/bitcoin/bitcoin/blob/master/src/pow.cpp
  28. U.S. Bureau of Labor Statistics, "CPI-U, U.S. city average, all items, NSA (CUUR0000SA0)": Sept 2000 = 173.7, Sept 2026 = 336.940. https://data.bls.gov/timeseries/CUUR0000SA0
  29. Bitcoin Wiki, "Controlled supply." https://en.bitcoin.it/wiki/Controlled_supply
  30. Cold Hard Sats, "Latest Bitcoin videos," feed refreshed Oct 18, 2026, 2:04 PM ET. https://coldhardsats.com/videos
  31. Bitcoin Core, "amount.h (COIN = 100,000,000 satoshis)," GitHub. https://github.com/bitcoin/bitcoin/blob/master/src/consensus/amount.h