The market hasn't been thrilled with Apple (AAPL 2.22%) this year. Its stock tanked after Trump's "Liberation Day" announcements, since its iPhones are predominantly made overseas, and its artificial intelligence (AI) upgrades have underwhelmed. Apple stock is trailing the market, down 21% year to date, even as the S&P 500 is starting to climb again.Is it as bad as the market thinks? Here's one metric you should see before you decide. Apple and the ecosystemApple has a wide ecosystem of products and service ...