Calamos Bitcoin Structured Alt Protection ETF - October (CBOO)
Calamos Bitcoin Structured Alt Protection ETF - October (CBOO) launched on October 7, 2025, and it is Calamos’s second annual-reset bitcoin structured product, following the success of its January sibling (CBOJ). Where CBOJ protects investors against losses exceeding 10 percent, CBOO goes further: it delivers 100 percent downside protection, meaning zero loss if bitcoin falls any amount during the outcome period, paired with a capped upside gain if bitcoin rises. The product resets every October, creating a new one-year outcome period at whatever cap and protection levels prevail in the market at that moment.
The CBOO design: full protection, capped gains
CBOO uses a two-layer options structure similar to CBOJ but with a crucial difference: the protection layer is stronger. An investor in CBOO buys an at-the-money put option, which means if bitcoin falls 50 percent, they lose nothing. If bitcoin falls 5 percent, they lose nothing. The floor is at current price. In exchange for this full protection, the upside cap is modest. At launch, CBOO’s cap for the first outcome period was 8.47 percent annualized. If bitcoin rises 40 percent in a year and CBOO’s cap is 8.47 percent, the investor captures 8.47 percent and forgoes the rest. This is the structure’s fundamental bargain: accept a measurable, known ceiling on gains to eliminate the risk of loss.
The two layers work together. The first layer is a call option bought at a near-zero strike, which gives investors nearly full participation in bitcoin’s upside up to the cap. The second layer is the protective put, purchased at the money. The cap is set by Calamos based on market conditions at the time of reset. In a high-volatility, high-interest-rate environment, options are expensive, and the cap shrinks. In a low-volatility, low-rate environment, the cap widens. CBOO’s cap will differ each October when it resets.
CBOO versus CBOJ
Both CBOJ and CBOO are Calamos structured bitcoin products, but the protection levels differ. CBOJ protects against losses exceeding 10 percent, meaning if bitcoin falls 9 percent, CBOJ holders lose 9 percent. CBOO protects against all losses, meaning even a 9 percent fall results in zero loss. This difference is meaningful. For conservative investors who cannot tolerate any drawdown—a retiree with no spare capital, or a pension fund with strict loss limits—CBOO is the appropriate choice. For investors who can handle a small decline but want to avoid catastrophic losses, CBOJ is less expensive and offers a wider upside cap. CBOJ’s initial expense ratio was 0.69 percent; CBOO’s is comparable.
Timing and the annual reset
CBOO resets every October, which creates the same timing dependency that affects all Calamos annual-reset products. An investor entering CBOO in late September 2025 enjoyed nearly a full year of protection and cap from that cohort. An investor entering CBOO in late October 2025 (just after the reset) immediately got a brand-new set of terms. The cap was different, the protection level was different, and the one-year clock had just restarted. This means CBOO investors face a calendar date (October) that marks a structural change in their position. Those who plan to hold CBOO long-term should understand that their protection and cap will shift each fall.
Spot bitcoin as the underlying
Like all Calamos structured bitcoin products, CBOO references spot bitcoin—specifically, the CME CF Bitcoin Reference Rate (BRRNY). This is not leveraged bitcoin, not a futures-based bitcoin product, not a bitcoin mining stock. CBOO is structured notation on the price of bitcoin itself. If bitcoin’s price in the spot market rises, the underlying asset appreciates, and CBOO’s value rises (subject to the cap). If bitcoin’s spot price falls, CBOO is protected. The fund does not hold physical bitcoin; it holds a structured contract that mimics bitcoin’s price movement within bounds.
Capital efficiency and implied volatility
The cap Calamos sets reflects implied volatility—the market’s expected range of bitcoin price movement. If the market prices in 50 percent volatility (high for bitcoin), the options to provide 100 percent protection are expensive, and the cap shrinks. If volatility falls to 30 percent, protection becomes cheaper, and the cap can widen. Sophisticated investors track the VIX and bitcoin volatility indices to anticipate whether forthcoming resets will offer attractive or unattractive cap levels. A reset during a period of elevated uncertainty might offer a wider cap (because full protection is more valuable to most investors, so Calamos can afford a smaller cap). A reset during complacency might offer a narrower cap.
The expense drag and total return expectation
CBOO’s expense ratio and the cost of the protective put combine to create drag on returns. In years when bitcoin is flat or down slightly, the cost of the fund’s structure (the put, the call, management fees) is a direct subtraction from returns. If bitcoin falls 5 percent and the fund costs 0.70 percent in expenses, the investor loses 5.70 percent in total. In years when bitcoin surges, the cap prevents investors from capturing large gains. The fund is most attractive in years of moderate bitcoin gains (say, 5 to 15 percent) or in years of sharp declines, where the protection shines. It is least attractive in sideways markets or years where bitcoin rallies so much that the cap is meaningless relative to what was foregone.
Liquidity and fund size
CBOO is a newer product with modest assets under management as of early 2026. Trading volumes on the Cboe BZX Exchange may be thinner than on mainstream bitcoin ETFs, and spreads can be wider. For retail investors buying small amounts, this is immaterial. For institutional investors placing large orders, the bid-ask spread and the lack of depth matter. CBOO is not as liquid as the largest, most popular bitcoin ETFs, and that is unlikely to change unless the fund grows substantially larger.
Who CBOO serves
CBOO is for investors who cannot afford to lose money on a bitcoin allocation. A foundation with a requirement to never report a loss, or a conservative portfolio manager who wants to own bitcoin but is constrained by risk limits, would find CBOO’s structure appealing. It is also for investors seeking to derisk a existing bitcoin position—selling some holdings and replacing them with a protected CBOO position locks in a floor. It is not for speculators, traders, or bitcoin believers expecting a multi-year bull market. The cap will cost too much in those scenarios.
Researching CBOO requires reading Calamos’s prospectus and fact sheet to see the specific cap and protection terms for the outcome period in question. Bitcoin price charts show past bitcoin performance, but that does not predict CBOO’s returns because CBOO’s cap depends on market conditions at reset. The SEC’s EDGAR filings contain the fund’s structure and performance, but as with all options-based products, the prospectus is the definitive source of how the fund works.