About a week ago, Tim Lee, one of Vox's senior editors and our lead technology writer, asked me if he could buy a small number of Bitcoins. I told him he could.

My thinking was this: it's true across the journalism industry, and also true at Vox, that reporters cannot invest in companies they cover. You can't be an auto reporter, say, and hold individual shares of Ford. But at the same time, reporters routinely invest in markets they cover. Real estate reporters own homes, and economy reporters are exposed to the dollar.

The question is which category Bitcoin fell into.

I ended up saying yes for a few reasons, and with a few conditions. First, Bitcoin is a large and liquid market that struck me as less like an individual stock and more like, well, a market unto itself. Second, the strange process of buying, holding and selling Bitcoins is, itself, part of the Bitcoin story — and it seemed to me there was value in understanding it, and even writing about it, firsthand. Third, we agreed that the value of the holdings would be capped around $2,000, so I didn't see this as an investment meant to generate personal financial gain. Fourth, we agreed that the holdings would always be clearly disclosed.

Today's article was meant to disclose Lee's purchase of Bitcoins. But it also made an argument for why Bitcoins are undervalued and might make some people very rich (though it paired this with an argument for why they were still probably a bad investment for most people). Putting those two together was a mistake — and it raised fair concerns about whether Lee's investment would color his coverage going forward.

This was my fault. While I don't think it's impossible to fairly cover Bitcoin while also holding some Bitcoins, the reason to make these rules blunt and general, rather than nuanced and specific, is to ensure there's no question about the motivations of the underlying coverage. The reader's ability to trust the writer is everything at Vox, as it is elsewhere.

So I apologize. I just got this one wrong. Lee will be selling his Bitcoins, and if there are any gains, they'll go to charity. Vox will continue to prohibit reporters from making investments in the firms they cover, except in the broadest cases (like a house, or an index fund), and when there's a question, we'll err against making the investment.