[coolguy4]

150 ETH/USD is normal forex notation.

The graph shows a currency pair. So one currency is being sold in exchange for the other.

When you see currency pairs like this, ETH/USD, the first currency (ETH) is the one being bought, the second currency (USD) is the one being sold. If the chart is going up, the first currency is becoming stronger against the second. If the chart is going down, the first currency is becoming weaker against the second.

In that light it does make sense mathematically. The currency being sold is the denominator and the currency being bought is the numerator. The value of the currency being bought, the numerator is directly proportional to the exchange value of the pair. The value of the currency being sold, the denominator, is inversely proportional to the exchange value of the pair

[jsmthrowaway]

That it took you that much to explain kind of illustrates the point, I think.