Section 04 / 12

Pricing Engine

Black-Scholes valuation in the SOL numeraire, realized volatility estimation, the parametric skew surface, and first- and second-order sensitivities.

Base Model

The pricing kernel is the Black-Scholes model expressed in the SOL numeraire. Since the underlying spot SS is quoted in SOL, no FX term enters the valuation. The model values of a vanilla European call CC and put PP are

C=S N(d1)−Ke−rτN(d2),(1)C = S\,N(d_1) - K e^{-r\tau} N(d_2), \tag{1} P=Ke−rτN(−d2)−S N(−d1),(2)P = K e^{-r\tau} N(-d_2) - S\,N(-d_1), \tag{2}

with

d1=ln⁡(S/K)+(r+12σ2)τστ,d2=d1−στ,(3)d_1 = \frac{\ln(S/K) + \left(r + \tfrac{1}{2}\sigma^2\right)\tau}{\sigma\sqrt{\tau}}, \qquad d_2 = d_1 - \sigma\sqrt{\tau}, \tag{3}

where SS denotes spot in SOL, KK the strike in SOL, τ\tau the time to expiry in years, σ\sigma the annualized volatility of log returns, rr the continuously compounded risk-free rate in the SOL numeraire, and N(⋅)N(\cdot) the standard normal cumulative distribution function.

Given short tenors and a SOL numeraire, the carry term rτr\tau is of negligible order relative to total variance σ2τ\sigma^2\tau. The engine sets r≈0r \approx 0, so that e−rτ≈1e^{-r\tau} \approx 1 and d1,2d_{1,2} reduce to functions of log-moneyness ln⁡(S/K)\ln(S/K) and total variance alone.

Realized Volatility Estimation

The volatility input is anchored to the realized volatility of the underlying. Given spot observations S0,S1,…,SnS_0, S_1, \dots, S_n sampled at a fixed interval, define log returns and their sample mean

ri=ln⁡ ⁣(SiSi−1),rˉ=1n∑i=1nri.(4)r_i = \ln\!\left(\frac{S_i}{S_{i-1}}\right), \qquad \bar{r} = \frac{1}{n}\sum_{i=1}^{n} r_i. \tag{4}

The annualized realized volatility estimator is

σrealized=Nn−1∑i=1n(ri−rˉ)2,(5)\sigma_{\text{realized}} = \sqrt{\frac{N}{n-1} \sum_{i=1}^{n} \left(r_i - \bar{r}\right)^2}, \tag{5}

where nn denotes the number of returns in the estimation window and NN the number of sampling intervals per year, scaling per-interval variance to an annual horizon under the assumption of independent increments. The sampling frequency, window length, and any bounds applied to the estimate are calibrated internally.

Volatility Skew Surface

A flat volatility across strikes is inconsistent with observed order flow and with the empirical return distribution. The engine maps strike and tenor to implied volatility through a second-order parametric surface in log-moneyness m=ln⁡(K/S)m = \ln(K/S):

σ(K,τ)=σATM(τ)+β⋅m+γ⋅m2,(6)\sigma(K, \tau) = \sigma_{\text{ATM}}(\tau) + \beta \cdot m + \gamma \cdot m^2, \tag{6}

where σATM(τ)\sigma_{\text{ATM}}(\tau) denotes the at-the-money term structure, β\beta the skew coefficient controlling the first-order slope in mm, and γ\gamma the curvature coefficient controlling smile convexity. β\beta and γ\gamma are calibrated to order flow and to the positive skewness of early-stage token returns, such that out-of-the-money calls are quoted at volatilities consistent with the empirical frequency of large positive moves. Their values are proprietary.

Sensitivities

The Greeks are the partial derivatives of model value with respect to its inputs. With φ(⋅)\varphi(\cdot) the standard normal density, under the base model:

ΔC=∂C∂S=N(d1),ΔP=∂P∂S=N(d1)−1.(7)\Delta_C = \frac{\partial C}{\partial S} = N(d_1), \qquad \Delta_P = \frac{\partial P}{\partial S} = N(d_1) - 1. \tag{7}

Delta (Δ\Delta) is the first-order sensitivity of value to spot.

Γ=∂2C∂S2=φ(d1)S στ.(8)\Gamma = \frac{\partial^2 C}{\partial S^2} = \frac{\varphi(d_1)}{S\,\sigma\sqrt{\tau}}. \tag{8}

Gamma (Γ\Gamma) is the second-order sensitivity to spot, identical for calls and puts, and maximal near the money as τ→0\tau \to 0.

ν=∂C∂σ=S φ(d1)τ.(9)\nu = \frac{\partial C}{\partial \sigma} = S\,\varphi(d_1)\sqrt{\tau}. \tag{9}

Vega (ν\nu) is the sensitivity to volatility, identical for calls and puts at a common strike.

ΘC=∂C∂t=−S φ(d1) σ2τ−rKe−rτN(d2).(10)\Theta_C = \frac{\partial C}{\partial t} = -\frac{S\,\varphi(d_1)\,\sigma}{2\sqrt{\tau}} - rKe^{-r\tau}N(d_2). \tag{10}

Theta (Θ\Theta) is the sensitivity to the passage of time. With r≈0r \approx 0 the second term vanishes and ΘC<0\Theta_C \lt 0 for long positions, reflecting the decay of extrinsic value toward expiry.

Model Limitations

Black-Scholes assumes geometric Brownian motion: normally distributed log returns, constant volatility, and continuous sample paths. Early-stage token returns violate each assumption:

  • Leptokurtosis and positive skewness. The empirical return distribution exhibits excess kurtosis and right skew; multi-sigma positive moves occur at frequencies far exceeding the lognormal law.
  • Stochastic, clustered volatility. Volatility is non-stationary and clusters around listing, liquidity migration, and order-flow shocks.
  • Jump discontinuities. Large orders against shallow liquidity induce discontinuous price moves that a pure diffusion cannot represent.

Consequently, the unadjusted kernel systematically underprices out-of-the-money upside on early-stage tokens. Oracle applies proprietary corrections on top of the base model to account for these effects. Equations (1) through (10) define the base kernel only; quoted premiums do not equal the raw Black-Scholes value.