1跪求详解par yield and bond yield and zero rates,我现在有点朦胧，跪求高手现身~
2Under what circumstances does a minimum variance hedge portfolio lead to no hedging at all？
3explain what a stop-limity  order to sell at 20.30 with a limit of 20.10 means.
4.what do you think would happen if an exchange started trading  contract in which the quality of the underlying asset was incompletely specified?
中英文均可答复，英文的话希望通俗一点，我才大一。。。求不无视不藐视。。谢谢