How can I track the best time to sell stocks and buy cryptocurrencies? (Closed)

My portfolio has a lot of stocks and mutual funds. I would like to sell a few percent of these “traditional” investments and buy cryptocurrencies. But I’m trying to find a way to calculate when is the best time to do this transfer.

Basically, what I want is to display a graph and set an alert to let me know:

1. when the stock price is high (compared to my fiat currency), and
2. If the price of the cryptocurrency is low (compared to the fiat currencies mentioned above)

First, what should we do in theory? Is there a way to create a graph that simplifies two lines into one? This is a two-line calculation that displays one line with a point very high on the y-axis when the two conditions above are true, and a graph that shows a point very low on the y-axis when the two conditions above are not true.

Now, how can you set up an alert to tell you when the chart above hits a year-to-date high, so that it tells you that now is a good time to sell your stock and buy the specified cryptocurrency?