import { SortinoRatioOptions } from '../schemas/SortinoRatioOptionsSchema';
import { SortinoRatioResult } from '../schemas/SortinoRatioResultSchema';
/**
 * Calculate Sortino Ratio
 *
 * Sortino = (Mean Return - Target Return) / Downside Deviation
 *
 * Unlike Sharpe, only penalizes downside volatility (returns < target).
 *
 * @param options - Returns, target return, risk-free rate, annualization
 * @returns Sortino Ratio and downside deviation metrics
 */
export declare function calculateSortinoRatio(options: SortinoRatioOptions): SortinoRatioResult;