This article describes a way to do payroll direct deposit with bitcoin.  Using Strike, it seems the fees are very cheap (mostly zero) and the dollar-to-bitcoin conversions seem to be at very normal rates.  (more…)

In a recent blog article I tried to make sense of a particular plunge in the price of bitcoin that happened on February 23, 2026.  This blog article looks at the opposite — a particular surge in the price of bitcoin that happened two days later.  (more…)

TLDR! If you are a merchant, you can skip to the end of this article to see what to do next if you are a merchant.  If you are a consumer, you can skip to the end of this article to see what to do next if you are a consumer.

Let’s suppose you want to pay for a cup of coffee using cryptocurrency.  Which cryptocurrency will work for this purpose?  Which payment mechanism will work for this cryptocurrency?

I predict that no cryptocurrency other than bitcoin will ever come into everyday use for what I call “walking around money”.  I further predict that on-chain bitcoin transfers will never come into into everyday use for “walking-around money”, but that a particular mechanism called “Lightning network” is the one that will come into everyday use.  In this blog article I explain these predictions.  (more…)

I recently made a small in-person point-of-sale purchase (see blog article) using Muun, which seems to be the most popular self-custodial Lightning network wallet for Android.  It seems to me that Muun is a must-have for the Android user who wants to carry a little “walking around money” for in-person incidental purchases such as the occasional cup of coffee.  (more…)

From time to time we see a big price change for bitcoin.  What is going on when this happens?  (more…)

So far as I am able to find out, Precision Ski and Sport is the only business in all of Summit County, Colorado that accepts payment in bitcoin.  As one might expect, the only way that this merchant accepts bitcoin is via the Lightning network.

As you can see from the cash register receipt shown at right, there is a “units” problem.   It is not true that 1462 bitcoin equal one dollar, as shown on the receipt.  1462 bitcoin actually add up to slightly more than one hundred million dollars.   It is also not true that I paid 7926 bitcoin.  If I had paid that number of bitcoin, I would have been handing over more than half a billion dollars.  (more…)

There have been several recent indicators of mainstream financial institutions choosing to treat bitcoin as a legitimate kind of asset.  A most recent indicator is a quarterly filing by Goldman Sachs, reported here by Yahoo Finance.  Goldman discloses that it now holds just over one billion dollars’ worth of bitcoin.

The filing is Goldman’s 4Q2025 13F.  Goldman chose not to hold the bitcoin directly, but instead chose to hold it through an ETF (exchange-traded fund).

In this article I discuss how to pick a cold wallet.  By this we mean a hardware wallet for management of your on-chain cryptocurrency.  (more…)

On April 13, 2022 Consumer Reports published a review reviewing five crypto wallets (hardware wallets for cold storage of on-chain cryptocurrency).  The review is by now 3½ years old so of course newer models of wallets are available, but one can still review CR‘s review, which is what I will try to do here.  What did they get right in that review?  What important selection factors, if any, did CR miss?

CR got a lot of things right.  The review nudged the reader away from leaving crypto on exchanges and toward on-chain storage using a cold wallet.  It helped the reader to appreciate that one wallet or another may turn out to be a better fit for the reader depending on the device (notebook computer, Android phone, iPhone) that the reader plans to use with the wallet.  The review helped the reader who is new to cold storage get a bit of an introduction to things like seed phrases and the fact that loss of a particular cold wallet need not entail loss of the cryptocurrency.

The chief thing CR missed was the open-source or proprietary nature of the firmware in the wallets. (more…)

One of the popular bitcoin exchanges is strike.me.  I guess they really want to minimize the risk that somebody could log in under somebody else’s account.  Here is how it went today when I logged in.

• Step 1.  On my notebook computer, I go to strike.me and I click “log in” and enter my email address.  What happens next is that it sends a secret code number to me by email (if my email address exists in their system).  It invites me to key in the secret code number.
• Step 2.  Check email again and again and again, eventually receiving the email with the secret code number.  It would be tempting to read the secret code number and key it in on the web page.  But it turns out that the secret code number is itself a URL to a web page.  Nowhere is it documented why you might want to click on this URL, but try it anyway.
• Step 3.  The URL launches a new web page that invites me to go find my TOTP (time-based one-time password) and key it in.  I do so.
• Step 4.  What appears next is a page that says I am still not authenticated.  I am invited to go find my mobile phone and launch the Strike app and click to authenticate myself.
• Step 5.  An email message arrives, letting me know that someone is trying to log in using my email address.
• Step 6.  I launch the Strike app and click to authenticate myself.
• Step 7.  I now see that I am logged in on my notebook computer.
• Step 8.  An email message arrives, letting me know that someone logged in using my email address.

I suppose depending on how you count it, this amounts to four-factor authentication.  To log in, I had to satisfy something like five conditions:

• I had to know the email address for logging in.  (In this case it is a custom email address specific to strike.me, so most people would not know the email address.)
• I had to be able to receive email at that email address.  (Most people would not not be able to receive email at that email address.)
• I had to be able to generate my time-based one-time password.  (Most people would not be in possession of my TOTP shared secret for strike.me.)
• I had to be able to lay my hands on my mobile phone, unlock it, launch the strike.me app, unlock it, and then click on the “authenticate” button.
• If this had all been a bad person somehow trying to hack my account, I would have received not one, not two, but three emails that might have tipped me off.

On the one hand, this seems a bit extreme and a bit annoying.   On the other hand, I get it that they would want to minimize the risk of somebody hacking my account.