/**
 * Compute simple period returns from a level series.
 * For each i>0: returns[i] = source[i]/source[i-1] - 1 when both values are finite and previous != 0.
 * The first element is always NaN. Invalid or non-finite inputs produce NaN at that position.
 * @param source Input level series (prices/equity)
 * @returns Float32Array of simple returns (same length as `source`)
 */
export declare function returns(source: ArrayLike<number>): Float32Array;
/**
 * Compute log returns from a level series.
 * For each i>0: logreturns[i] = log(source[i]/source[i-1]) when both values are finite and previous>0.
 * The first element is always NaN. Invalid or non-positive previous values yield NaN.
 * @param source Input level series (prices/equity)
 * @returns Float32Array of log returns (same length as `source`)
 */
export declare function logreturns(source: ArrayLike<number>): Float32Array;
/**
 * Compute cumulative compound returns from a returns series, skipping NaNs.
 * Cumulative return at i is prod_{j<=i, r_j finite} (1+r_j) - 1; NaN inputs leave an output NaN at that position.
 * @param returns Simple returns series
 * @returns Float64Array of cumulative returns
 */
export declare function cumreturns(returns: ArrayLike<number>): Float64Array;
/**
 * Compute the compound annual growth rate (CAGR) from a returns series.
 * Ignores NaNs. `freq` is the number of periods per year (default 252).
 * @param returns Simple returns series
 * @param freq Periods per year (default 252)
 * @returns CAGR as a number, or NaN when insufficient data
 */
export declare function cagr(returns: ArrayLike<number>, freq?: number): number;
/**
 * Aggregate irregular (event-aligned) returns into calendar-day returns.
 *
 * The function groups `returnsArr` by calendar day (optionally shifted by `tzOffsetMinutes`),
 * compounds returns within each day (prod(1+r)-1) and returns a continuous range of days
 * from the minimum to the maximum observed day. Missing days are filled with zero returns.
 *
 * @param tsMs Array of timestamps (ms since epoch) aligned to `returnsArr`
 * @param returnsArr Array of simple returns aligned to `tsMs`
 * @param tzOffsetMinutes Optional timezone offset in minutes (default 0, UTC)
 * @returns Object { days: number[], dailyReturns: Float32Array }
 */
export declare function dailyreturns(tsMs: ArrayLike<number>, returnsArr: ArrayLike<number>, tzOffsetMinutes?: number): {
    days: number[];
    dailyReturns: Float32Array<ArrayBuffer>;
};