How is the stock value of an index fund like VOO determined?

Question

I understand that an Index Fund tracks an existing index (e.g., S&P500) by just buying the same stock in an equal proportion that the index has, and the fact that we can assume that the Index Fund company (e.g., Vanguard) owns the stock.

However, I don't understand how the stock value of the Index Funds (e.g., VOO) is calculated relative to its securities.

Is just like any other stock (i.e., speculative value) or there's a specific way to get the value? Maybe a ratio?

Let's put it with an example:

Today S&P500 is at 4100. Why is VOO at $370?

Answer 1

Essentially, although an ETF trades throughout the day, it's value is centred around its NAV, reflected as a price per share, computed as such: NAV = (Assets − liabilities)/shares outstanding)

Therefore, ETF values depend on the shares in circulation.

In general, you don't need to pay much attention to the fund’s price, as no matter how much you pay for a share (different ETFs tracking SPX will have different prices), because the value of your shares will increase at the same rate (at least in a very narrow range). Where it could matter is situations where you cannot invest in fractions of shares in which case smaller values will allow you to buy smaller amounts.

Simplified, if the index rises on average 7%, the value of your shares will also increase by 7%, no matter which fund of that particular index you’re invested in.