# 数学经济|ECON113 Mathematical economics代写 warwick代写

To establish the connection between martingale measures and arbitrage, we must restrict ourself to a special class of trading strategies which is from the real world financial market point of view very natural. Let us assume that at time $t_{0}$ a trader enters a market ( only consisting of tradeable assets ) and buys assets according to $\varphi_{t_{0}}$. Then the worth of his portfolio at time $t_{0}$ is
$$V_{t_{0}}(\varphi)=\varphi_{t_{0}} \cdot X_{t_{0}} .$$
Now he chooses not to change anything with his portfolio until time $t_{1}$. Then his portfolio at time $t_{1}$ still consists of $\varphi_{t_{0}}$ and hence has worth
$$V_{t_{1}}(\varphi)=\varphi_{t_{0}} \cdot X_{t_{1}}$$

At time $t_{1}$ though he chooses to rearrange his portfolio and reinvest all the money from $V_{t_{1}}(\varphi)$ according to $\varphi_{t_{1}}$. After this rearrangement the worth of his portfolio calculates as
$$V_{t_{1}}(\varphi)=\varphi_{t_{1}} \cdot X_{t_{1}} .$$
Since he only used the money from $V_{t_{1}}(\varphi)$ and didn’t consume any of the money the two values from must coincide. Hence we have

myassignments-help数学代考价格说明

1、客户需提供物理代考的网址，相关账户，以及课程名称，Textbook等相关资料~客服会根据作业数量和持续时间给您定价~使收费透明，让您清楚的知道您的钱花在什么地方。

2、数学代写一般每篇报价约为600—1000rmb，费用根据持续时间、周作业量、成绩要求有所浮动(持续时间越长约便宜、周作业量越多约贵、成绩要求越高越贵)，报价后价格觉得合适，可以先付一周的款，我们帮你试做，满意后再继续，遇到Fail全额退款。

3、myassignments-help公司所有MATH作业代写服务支持付半款，全款，周付款，周付款一方面方便大家查阅自己的分数，一方面也方便大家资金周转，注意:每周固定周一时先预付下周的定金，不付定金不予继续做。物理代写一次性付清打9.5折。

Math作业代写、数学代写常见问题

myassignments-help擅长领域包含但不是全部: