考慮違約風險與隨機利率模型下的匯率連結外幣資產選擇權定價

Abstract

匯率衍生性金融商品皆屬於店頭市場（over-the-counter, OTC）交易，且匯率波動與本國及外國之利率有一定的關係，在評價匯率衍生性金融商品時，若忽略交易對手違約風險與利率波動及匯率之相關性，將有失適用性。因此本文延伸有違約風險的匯率選擇權在HJM（Heath, Jarrow and Morton, 1992）遠期利率模型架構下的評價公式，考量上述兩個因子來評價。本研究在信用風險因子的模型設定中，進一步加入HJM遠期利率模型架構，進而求得隨機利率下考慮違約風險之匯率連動選擇權評價模型，以提供投資人來因應匯率風險管理的避險需求。本文將此評價模型應用於最常見的四種匯率連結外幣資產選擇權爲範例，探討其在隨機利率與信用風險下合理的價格。

Most of foreign currency derivatives are traded in the over-the-counter (OTC) and thus is not equipped with the mechanism of margin account and marking to market. Moreover, the exchange rate is greatly affected by the dynamics of both domestic and foreign interest rates. Therefore, if the foreign currency derivatives are priced without the consideration of the counterparty default risk and interest rate, their pricing may cause some pricing error. To solve this problem, this paper presents a pricing formula for foreign currency options with the consideration of the counterparty default risk and interest rate risks within the HJM interest rate model.