This article was displayed on the ChosunBiz MoneyMove (MM) site at 3:53 p.m. on Mar. 11, 2026.
As shares of Sphere, known as an overseas vendor for SpaceX, have surged for days on the KOSDAQ, investors in its convertible bonds (CB) have booked more than 14 times their money. Sphere is also expected to enjoy gains by reselling CBs it bought back through a call option as the stock climbs.
According to investment banks (IB) and the Financial Supervisory Service's electronic disclosure system on the 11th, Sphere recently received a conversion request for part of the fourth CB tranche issued in March last year. The conversion price is 3,448 won, and given the current share price in the 50,000-won range, the investor's one-year return comes to 1,450%.
Sphere issued 15 billion won worth of fourth-tranche CBs in March last year. The terms carry a 3% coupon and 6% yield to maturity. Maturity is scheduled for Mar. 7, 2028. The investor was Withwin Investment's Withwin Investment Association No. 78.
With this investment, the Withwin Investment Association is projected to earn about 100 billion won in profit within a year. The current market value of roughly 2 million Sphere shares obtained by converting 6.9 billion won worth of CBs is about 105 billion won.
Behind the CB investors' ability to book large gains in a short period are Sphere's surging share price and the CB's refixing terms.
Sphere has been categorized as a theme stock since taking on an overseas vendor role for U.S. aerospace company SpaceX, and its share price has soared since last year. Sphere's shares spiked ahead of Mar. 7, when the CB became convertible. The stock, which was in the 8,000-won range at the time of the CB issuance, moved sideways through the end of last year, but after topping the 10,000-won range in December last year, it rose fivefold in about three months to the 50,000-won range.
Typically, when a CB issuer's share price jumps, the conversion price is adjusted upward, reducing expected gains, but the Withwin Investment Association maximized returns by being able to convert at the initially set low price.
Sphere's fourth-tranche CBs did not include conversion price refixing tied to share price movements. The conversion price would be adjusted only if new shares were issued through a rights offering, bonus issue, dividends, or capital transfer, or if mezzanine securities were issued at or below the conversion price.
In effect, the terms at issuance were excessively favorable to investors. Even with the share price in the 8,000-won range at the time, they could convert at 3,448 won. There may be no refixing, but the conditions can still be seen as advantageous to investors.
Meanwhile, part of the profits generated from the CBs is expected to flow back to the issuer, Sphere. That is because, aside from the portion converted this time, Sphere has already bought back most of the tranche. Sphere exercised a call option on 7.5 billion won worth of the fourth-tranche CBs over two days on the 3rd and 4th. Sphere plans to resell the CBs later.
Cases of repurchasing CBs with guaranteed gains through call options and selling them to third parties for profits have been recurring recently amid a surging stock market. KOSDAQ-listed Woori Technology earned a 10 billion won gain from a CB resale last month, and on the 10th it succeeded in reselling CBs for about 37 billion won that it had bought for roughly 5 billion won. If Sphere also resells CBs, it is expected to book profits in the hundreds of billions of won.
A source in the capital markets industry said, "Sphere appears to have increased its financial burden after recently carrying out an investment in a nickel smelter," and added, "We expect the CB sale proceeds to give it some breathing room."