# AI For Trading:.NET Asset Value and Expense Ratios and Open End Mutual Funds (38)

## Net Asset Value(资产净值)

NAV: Net Asset Value
AUM: Assets Under Management (管理资产)

NAV = (AUM - Expenses) / (number of shares)

### 练习题：

Calculate the NAV of a fund given the following information: The fund holds 4000 shares of stock A at $5 per share; and 3000 shares of stock B at$4 per share. The Gross Expense Ratio of the fund is 0.1% (0.001) of the assets under management. Assume there are no other liabilities. There are 1000 shares of the fund.

A：$32.00 B:$31.97
C: $32000 B:$31968

The value of stock A invested is $5 x 4000 shares =$20 000.
The value of stock B invested is $4 x 3000 =$12 000. Total assets under management (AUM) is $20 000 +$12 000 = $32 000. The liabilities are the Gross Expense Ratio x AUM = 0.001 x 32 000 =$32.
So the Net Asset Value is ($32 000 -$32)/1000 = $31968/1000 =$31.97

## Expense Ratios

AUM: Assets Under Management
Gross Expense Ratio: Expenses / AUM (总开支比率)
Net Expense Ratio: (Expenses - Discounts) / AUM（净开支比率）

## Open End Mutual Funds(开放终端共同基金)

Most mutual funds are open end funds, meaning that they allow investors to redeem(赎回) their shares in the fund. Open end funds may keep some of the assets under management as cash, to improve liquidity and handle redemptions. The total return of the fund is a weighted average of the portfolio return and the interest earned from the cash.