Metaplanet MARS and MERCURY: Japan's Bitcoin Preferred Stocks Explained

Short answer: MARS and MERCURY are the two preferred stocks of the Japanese bitcoin company Metaplanet. MERCURY pays a fixed 4.9% in yen, can be converted into common stock and has been held by six institutional investors since December 2025, not on an exchange. MARS is meant to pay a monthly adjusted rate but has not been issued yet. Right now you can buy neither.

You read about "Japan's Strategy" and its preferred stocks MARS and MERCURY and look for them in your brokerage account in vain. That's not your broker's fault. Metaplanet MARS and MERCURY are a plan that has got stuck on stock exchange rules in Japan. Here you'll see what both securities are meant to be, what of it already exists, how well MERCURY is covered and which date in January 2027 will matter.

Who is Metaplanet?

Metaplanet is a listed company from Tokyo (stock: 3350.T, Tokyo Stock Exchange Standard). It used to run hotels; since April 2024 it has been buying bitcoin as its main reserve. On Sep 30, 2026, Metaplanet held 44’000 BTC, one of the largest holdings of any listed company after Strategy. How Metaplanet got there is shown in the profile of Metaplanet stock.

Besides that, Metaplanet earns money selling bitcoin options. Mainly through this, the group had revenue of about ¥8.9 billion in 2025. So far it has financed its bitcoin mainly through new common stock, bonds and a loan secured by bitcoin as collateral. In October 2026, ¥52 billion in zero-coupon convertible bonds due 2031 were added.

The common stock has traded below the value of its bitcoin for months: according to the treasury profile of Metaplanet, the mNAV is 0.57×. Selling new common stock would therefore cost shareholders bitcoin per share. Instead, Metaplanet bought back 96 million of its own shares in October 2026. Preferred stock is meant to finance growth without this dilution, as at Strategy. How treasury companies work in general is explained in the article on bitcoin treasury companies.

Metaplanet MARS and MERCURY at a glance

As of Nov 13, 2026. Source: Metaplanet announcements of Nov 20, 2025, Dec 30, 2025, Jun 8, 2026 and Oct 5, 2026. Live data on all securities on the Digital Credit page.

The names are deliberate: Metaplanet wants them to show each security's role. MARS is meant to be a calm, running income. MERCURY is meant to combine a fixed rate with the chance of gains in the common stock.

MERCURY: a fixed rate with a conversion right

MERCURY is the only one of the two that actually exists. Metaplanet sold it on Dec 29, 2025 directly to six funds, without an exchange, including Capital Group's SMALLCAP World Fund and several Anson funds. They paid ¥900 per share, 10% below the ¥1’000 stated amount.

What MERCURY pays

Each share receives 4.9% on ¥1’000, which is ¥12.25 per quarter or ¥49 a year. For all 23.61 million shares together, that costs Metaplanet about ¥1.16 billion a year, about €6.5 million. The dividends up to the record date of Dec 31, 2026 have already been declared; the next payment is on Jan 15, 2027.

They are paid not out of profit but out of the capital reserve Metaplanet built up from earlier share sales. The reason: under Japanese accounting, profit swings with the bitcoin price, the reserve does not. For comparison: Metaplanet's 2025 revenue was about eight times the annual MERCURY dividend.

The conversion right

You can have each MERCURY share converted into common stock at any time. The conversion price is ¥1’000: for one MERCURY share you get one common share. That only pays off once the common stock is above ¥1’000.

On Nov 12, 2026 it closed at ¥229. So it would have to more than quadruple before conversion is worth anything. Today the conversion right is a distant option, not part of the return. The same applies to Strategy's STRK, whose conversion price is also far above the stock price; in return, STRK pays 8% instead of 4.9%.

MARS: the variable security that doesn't exist yet

MARS is meant as the counterpart to STRC (Stretch). The rate is to be reset every month: higher if MARS trades below its stated amount, lower if it trades above. That is meant to keep the price close to the stated amount and the dividend flowing steadily. MARS cannot be converted into common stock.

Shareholders approved the class in December 2025. Not a single share has been issued to date. Metaplanet has not published the stated amount, the rate or the exact rules for adjustments.

Why it is stuck

In May 2026, CEO Simon Gerovich postponed the listing plans for MARS and MERCURY. His reasoning: Japanese companies usually pay dividends once or twice a year, and a monthly payout does not fit established processes. In addition, the Tokyo Stock Exchange requires preferred dividends to be paid from a lasting business. Metaplanet's options business has only existed since late 2024.

Since then, Metaplanet has been looking for other routes:

1. Its own securities firm. In June 2026, Metaplanet announced the purchase of the Tokyo bond broker Siiibo Securities for ¥2.1 billion, to bring bonds and preferred stock to investors itself.
2. A detour through the US. In August 2026, Metaplanet announced it would take over the Nasdaq company Super League with 2’100 bitcoin and rename it "Superplanet". Its shareholders approved in October 2026, and completion is planned for the fourth quarter of 2026. Preferred stock in dollars is to be issued through Superplanet.
3. Proving creditworthiness. In the third quarter of 2026, Metaplanet sold 10’000 BTC and then bought 11’000 back, to show that it can turn bitcoin into cash if it has to. The goal is a credit rating that makes new preferred stock and bonds easier.

Rule of thumb: MERCURY is a finished security without an exchange. MARS is an idea without a security. You can buy neither today.

How safe is MERCURY? Coverage and ranking

Like all bitcoin preferred stocks, MERCURY is not secured by specific bitcoin. Its safety comes from Metaplanet's holdings and from the ranking: creditors are paid first, then MARS, then MERCURY, and common shareholders last. Because MARS does not exist yet, nothing stands between the debt and MERCURY today.

As of Nov 13, 2026. 44’000 BTC at €64’078 (¥11.34 million) per bitcoin. Claims per Metaplanet's announcement of Oct 5, 2026, updated for the share buyback in October 2026; Metaplanet does not publish a total debt figure.

If bitcoin falls 70%, Metaplanet's bitcoin still just about cover MERCURY exactly. That is a thicker cushion than most traded securities have: Strategy's STRK is at 3.3×, Strive's SATA at 2.2×. How the securities compare side by side is shown in Strive SATA and SATS explained for Strive and in the overview in the guide Digital Credit explained for all of them.

And compared with the Power Law?

The Power Law floor was about €60’570 (CHF 55’920) on Nov 13, 2026, only 6% below the price. Even at the floor, Metaplanet's bitcoin would still cover MERCURY about 3.2 times. MERCURY would only stop being fully covered if bitcoin fell a good two thirds below the floor. How the floor is calculated is in the methodology; it is a model, not a guarantee.

The deadline in January 2027

The most important point in MERCURY's terms is a deadline. If MERCURY is not listed in Tokyo by the 20th business day after Dec 29, 2026, around the end of January 2027, holders may demand that Metaplanet buy back their shares. The price: ¥1’000 per share plus unpaid dividends.

For the funds, that would be a good deal. They paid ¥900 and would get ¥1’000 back, 11% more, plus the dividends. Metaplanet itself writes that a large payment it cannot control may then fall due.

Metaplanet has not said whether MERCURY will be listed by then. Given the statements of May 2026 and the detour through the US, a Tokyo listing by January looks unlikely. It is not certain.

What if MERCURY came to the exchange?

Suppose MERCURY traded in Tokyo at the issue price of ¥900. Then a purchase would look like this:

Whether a yen dividend of just over 5% suits you depends on how you judge the yen risk and the conversion option. How much cash flow a traded preferred stock makes from your amount you can work out here:

The risks of MARS and MERCURY

1. No market

Without an exchange there is no price and no way to sell. MERCURY holders can only convert, wait for the listing or, from the end of January 2027, demand redemption.

2. Yen risk

Both securities are denominated in yen. For investors in euros or francs, every dividend swings with the exchange rate.

3. Ranking behind MARS

If Metaplanet later issues MARS, MERCURY slips one place back. Every yen of MARS lowers MERCURY's coverage.

4. Loans with bitcoin as collateral

Metaplanet has a credit line of up to $500 million secured by bitcoin as collateral. If the price falls sharply, the lenders can demand more collateral or sell it. Those bitcoin are then no longer available to preferred shareholders.

5. Open plans

The terms of MARS are unknown, and the Superplanet takeover is not complete. What will end up buyable in a brokerage account in Germany, Austria or Switzerland is not yet settled. How preferred dividends are taxed in your country depends on where you live and on your account; when in doubt, ask a tax adviser.

Who are MARS and MERCURY interesting for?

Today, for anyone who wants to understand Metaplanet as a shareholder or observer. The preferred stocks show how Metaplanet intends to grow, and the January 2027 deadline can move the balance sheet.

As an investment, they only come into question once they trade on an exchange. Until then you'll find variable-rate securities at Strategy (STRC) and Strive (SATA), and convertible ones at Strategy (STRK). Terms such as stated amount, cumulative or rank are explained in the Digital Credit glossary.