每天都想出坑的铁头娃 · 2021年03月30日
问题如下：
If the correlation between foreign-currency asset returns and movements in the exchange rate is increasing, the expected domestic-currency returns will:
选项：
A. increase
B. decrease
C. unchange.
解释：
C is correct.
考点：Currency Risk & Portfolio Return and Risk
解析：correlation的增加会影响domestic-currency risk，而不会影响returns。写出公式就能理解了：
，
与其说是unchange，我觉得说unclear更好一点。
Hertz_品职助教 · 2021年03月30日
嗨，努力学习的PZer你好：
同学你好~
本题考查的知识点是return的计算公式（如下图）
题目问的是ρ变大的时候对expected domestic-currency returns的影响，根据return的计算公式（如下图），可知Rdc是不受ρ的影响的哈，所以说是unchange. （根据公式也可知ρ是影响risk的大小的）
同学为何会理解为影响是unclear，可以稍微说一下，咱们再做探讨哈~
----------------------------------------------虽然现在很辛苦，但努力过的感觉真的很好，加油！
NO.PZ2018111501000007 问题如下 If the correlation between foreign-currenasset returns anmovements in the exchange rate is increasing, the expectemestic-currenreturns will: increase crease unchange. C is correct.考点CurrenRisk Portfolio Return anRisk解析correlation的增加会影响mestic-currenrisk，而不会影响returns。写出公式就能理解了R=(1+RFC)(1+RFX)−1R_{}=(1+R_{FC})(1+R_{FX})-1R=(1+RFC)(1+RFX)−1 ，σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX)\sigma^2(R_{})\approx\sigma^2(R_{FC})+\sigma^2(R_{FX})+2\sigma(R_{FC})\sigma(R_{FX})\rho(R_{FC},R_{FX})σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX) 请问老师，Rfc和Rfx相关性增大，对R完全不产生影响，还是产生影响不确定，可能变大也可能变小？
NO.PZ2018111501000007 问题如下 If the correlation between foreign-currenasset returns anmovements in the exchange rate is increasing, the expectemestic-currenreturns will: increase crease unchange. C is correct.考点CurrenRisk Portfolio Return anRisk解析correlation的增加会影响mestic-currenrisk，而不会影响returns。写出公式就能理解了R=(1+RFC)(1+RFX)−1R_{}=(1+R_{FC})(1+R_{FX})-1R=(1+RFC)(1+RFX)−1 ，σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX)\sigma^2(R_{})\approx\sigma^2(R_{FC})+\sigma^2(R_{FX})+2\sigma(R_{FC})\sigma(R_{FX})\rho(R_{FC},R_{FX})σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX) 老师，如果相关性上升，不就意味着两者同涨或者同跌，感觉公式，同涨会使R上升，如果同跌，那负负得正，不也会使R上升
NO.PZ2018111501000007 问题如下 If the correlation between foreign-currenasset returns anmovements in the exchange rate is increasing, the expectemestic-currenreturns will: increase crease unchange. C is correct.考点CurrenRisk Portfolio Return anRisk解析correlation的增加会影响mestic-currenrisk，而不会影响returns。写出公式就能理解了R=(1+RFC)(1+RFX)−1R_{}=(1+R_{FC})(1+R_{FX})-1R=(1+RFC)(1+RFX)−1 ，σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX)\sigma^2(R_{})\approx\sigma^2(R_{FC})+\sigma^2(R_{FX})+2\sigma(R_{FC})\sigma(R_{FX})\rho(R_{FC},R_{FX})σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX) 根据公式，Rfc和Rfx都在上升，那R不是也在上升吗？R=（1+Rfc）*（1+Rfx）-1，前两项都变大，则R不应该也变大吗？
NO.PZ2018111501000007 问题如下 If the correlation between foreign-currenasset returns anmovements in the exchange rate is increasing, the expectemestic-currenreturns will: increase crease unchange. C is correct.考点CurrenRisk Portfolio Return anRisk解析correlation的增加会影响mestic-currenrisk，而不会影响returns。写出公式就能理解了R=(1+RFC)(1+RFX)−1R_{}=(1+R_{FC})(1+R_{FX})-1R=(1+RFC)(1+RFX)−1 ，σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX)\sigma^2(R_{})\approx\sigma^2(R_{FC})+\sigma^2(R_{FX})+2\sigma(R_{FC})\sigma(R_{FX})\rho(R_{FC},R_{FX})σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX) 这里说道的mestic risk↑，能不能等价于foreign risk也↑呢
NO.PZ2018111501000007问题如下 If the correlation between foreign-currenasset returns anmovements in the exchange rate is increasing, the expectemestic-currenreturns will: increase crease unchange. C is correct.考点CurrenRisk Portfolio Return anRisk解析correlation的增加会影响mestic-currenrisk，而不会影响returns。写出公式就能理解了R=(1+RFC)(1+RFX)−1R_{}=(1+R_{FC})(1+R_{FX})-1R=(1+RFC)(1+RFX)−1 ，σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX)\sigma^2(R_{})\approx\sigma^2(R_{FC})+\sigma^2(R_{FX})+2\sigma(R_{FC})\sigma(R_{FX})\rho(R_{FC},R_{FX})σ2(R)≈σ2(RFC)+σ2(RFX)+2σ(RFC)σ(RFX)ρ(RFC,RFX) • If the correlation 0, then Rec returns are amplifieRey returns, anit willin turn increases mestic investor's return volatility.• If the correlation 0, then Rec returns are mpeneRey returns, anitwill in turn creases mestic investor's return volatility.
