Bitcoin's Quantum Problem Is Real. Your RMD Problem Is Sooner.

An advisor we work with recently sat down with a retiree whose IRA is worth about $1 million. Half of it, about $500,000, is in Bitcoin.

That can go either way. Bitcoin could double. It could also be cut in half. Either way, there's a date on the calendar that doesn't care which way it goes: December 31, the day the IRS uses to set next year's required minimum distribution, or RMD.

Everyone online is arguing about whether quantum computers will "kill" Bitcoin. That's a real debate, and we'll get to it. But for a retiree with half an IRA in Bitcoin, quantum is the slow-moving threat. The RMD is the one with a clock on it.

The example is based on a real situation, with the numbers rounded and personal details left out.

First, the Quantum Problem in Plain English

Bitcoin is protected by a kind of math lock called elliptic curve cryptography. Every Bitcoin has a private key, a secret, and a public key, which can be shown to the world. Today's computers can't work backward from the public key to the secret. A large enough quantum computer, in theory, could.

That theory got a lot less theoretical this year. On March 30, 2026, Google's Quantum AI team, working with researchers from Stanford and the Ethereum Foundation, published a paper estimating that breaking Bitcoin's lock would take fewer than 500,000 physical qubits and could run in minutes. Earlier estimates were about 20 times higher. The paper hasn't been peer reviewed.

Here's the reality check: today's largest quantum machines have roughly a thousand physical qubits or fewer, and they make far too many errors to run this attack. Nobody can break Bitcoin today. The argument is about when, not whether it's happening now.

What's exposed if that day comes? Blockchain analytics firm Glassnode estimated in May that about 6 million Bitcoin, roughly 30% of the supply, sit in addresses whose public keys are already visible. Other trackers put it closer to 7 million. That includes about 1 million coins believed to belong to Satoshi Nakamoto, Bitcoin's anonymous creator, that haven't moved in more than 15 years.

Wall Street has noticed too. BlackRock and Coinbase both list quantum computing as a risk in their regulatory filings.

Can Bitcoin Fix It?

Probably, but slowly. In February, Bitcoin developers formally added a proposal called BIP-360 to the list of official upgrade proposals. It would create a new kind of address that keeps the public key hidden. Its authors call it a "first step." Quantum-safe signatures would come later.

It's still a draft. It isn't switched on. Bitcoin has no CEO, so any change needs broad agreement among developers, miners and users. The last major upgrade, Taproot, took years of debate before it went live in November 2021.

There's also an ugly unsolved question: what happens to Satoshi's coins and other abandoned coins that never get moved to safer addresses? Some developers want to freeze them. Others say that breaks Bitcoin's promise that nobody can touch your coins. That fight hasn't been settled.

The "Competing Currencies": Who's Actually Competing?

If Bitcoin is vulnerable, won't something quantum-proof replace it? Here's how the challengers actually stack up.

• Coins built to be quantum-safe. The best known is the Quantum Resistant Ledger, or QRL, which has used quantum-resistant signatures since 2018. Its total value is about $94 million. Bitcoin's is about $1.6 trillion, more than 17,000 times bigger. Being quantum-proof hasn't made anyone switch. And if Bitcoin upgrades, the selling point mostly goes away.
• Stablecoins. These are digital dollars run by private companies, and they're the real growth story. About $302 billion was in circulation as of October 19, led by Tether (about $183 billion) and USDC (about $72 billion). Congress passed the GENIUS Act in July 2025 to regulate them. But they compete with checking accounts and wire transfers, not with Bitcoin as a store of value. A digital dollar is still a dollar.
• A government digital dollar. Not happening here, for now. A January 2025 executive order barred federal agencies from creating one. China and other countries are testing their own.

The takeaway: the competition isn't one shiny new coin. It's a slow sorting of jobs. Stablecoins handle payments. Bitcoin is betting on being "digital gold." Quantum is a test of whether Bitcoin can upgrade itself in time.

Now the Ticking One: Your RMD

Here's how required withdrawals work. Once you hit RMD age, 73 if you were born between 1951 and 1959, or 75 if you were born in 1960 or later, the IRS makes you take a minimum amount out of your traditional IRA every year. The amount is your December 31 balance from the year before, divided by a factor from the IRS life-expectancy table. At 73, the factor is 26.5.

For our $1 million IRA at age 73:

• $1,000,000 ÷ 26.5 = about $37,700 that must come out this year, and it's taxed as ordinary income.

Simple enough. Now add Bitcoin.

Scenario 1: Bitcoin Crashes After New Year's

Say Bitcoin falls 50% in January. The Bitcoin half drops from $500,000 to $250,000, and the account is now worth $750,000.

The RMD is still $37,700. It was locked in on December 31. Instead of about 3.8% of the account, you're now pulling out more than 5%. And if the cash comes from selling Bitcoin, you're selling at the bottom.

Think that's far-fetched? Bitcoin opened 2026 at about $87,800. By June 30 it was about $59,000, down roughly a third in six months. It has done far worse before: down about 84% in 2018 and about 77% in 2022.

Scenario 2: Bitcoin Doubles Before December 31

This sounds like the happy ending. The Bitcoin half grows to $1 million, and the account hits $1.5 million.

Next year's withdrawal jumps to about $56,600 at the same age, almost $19,000 more in taxable income you didn't ask for. If it triples, the account is $2 million and the RMD is about $75,500.

That extra income can push you into a higher tax bracket and make more of your Social Security taxable. It can also raise your Medicare premiums two years later. For 2026, the Medicare surcharges start at incomes above $109,000 for single filers and $218,000 for married couples filing jointly.

The Quiet Trap: Paying RMDs From the "Safe" Half

Plenty of people avoid selling Bitcoin by taking every RMD from the other half of the account. It feels smart. But each year the safe money shrinks and Bitcoin becomes a bigger share. Without anyone deciding it, a 50% bet slowly becomes 60%, then 70%.

And skipping the RMD isn't an option. Miss it and the penalty is 25% of what you didn't take. It drops to 10% if you fix it within two years.

How to Defuse It

None of these is right for everyone. They're the questions worth bringing to your advisor and tax preparer.

1. Know your December 31 number before it's set. Check the account in November or early December. A big run-up means a bigger RMD next year, and you'll have a few weeks to plan around it.
2. Keep an "RMD reserve." Hold two or three years of withdrawals in cash or short-term Treasuries inside the IRA. For this account, that's roughly $75,000 to $113,000. Then a Bitcoin crash doesn't force a sale.
3. You can't pick the amount, but you can pick the day. The RMD can come out any time during the year. If Bitcoin spikes in March, selling then gets you more for each coin than waiting until December.
4. Take the shares instead of cash. Many custodians let you move investments, like shares of a Bitcoin fund, straight from the IRA to a regular brokerage account. It counts toward your RMD and you keep the position. It's still taxed at that day's value, so you need cash on hand for the tax bill.
5. Convert to a Roth in down years. Moving money to a Roth IRA after a drop means paying tax on the lower value. Future growth is tax-free, and Roth IRAs have no required withdrawals during your lifetime. Once RMDs start, you have to take that year's RMD before converting.
6. Give it away tax-free. At 70½ or older, you can send up to $111,000 in 2026 straight from your IRA to a qualified charity. It counts toward your RMD and doesn't count as income.
7. Decide how much one bet should carry. This isn't about whether Bitcoin is good or bad. It's about whether half your retirement should ride on one asset that has dropped by a third or more within a single year.
8. Check how you own it. A Bitcoin fund in a regular IRA trades like a stock and is easy to sell or move. A self-directed crypto IRA may have different fees, valuation methods and rules for moving coins out. Know which one you have before you need to act.

The Bottom Line

Quantum computing may someday force Bitcoin to change, and the developers are working on it. That's a story worth watching. But if Bitcoin is half your IRA, the risk you can actually plan for has a date on it: December 31, every year, for the rest of your life. The math is simple. Most people just never run it until the bill is due.

Want help running your own numbers? Bring your questions to our Setting the Stage for 2027 Retirement Webinar, or talk to an advisor.

Figures as of October 19, 2026, unless noted, from the IRS (Uniform Lifetime Table, Notice 2025-67), Medicare, Google Quantum AI, Glassnode, CoinDesk, Ars Technica, the Bitcoin BIPs repository, CoinGecko, DefiLlama and Yahoo Finance price data. RMD examples are simplified and assume one traditional IRA, no other income and the account owner at age 73. Past performance doesn't guarantee future results. Educational information, not individualized tax or investment advice; nothing here is a recommendation to buy or sell any security or cryptocurrency. Cover image: AI-created, realistic editorial scene illustrating the story; not a photograph of an actual reader or client.