Monopolies can make investors quite wealthy, and the FTSE 100 has a few to capitalise on. Normally, regulators don’t allow these types of businesses, but there are some exceptions. And with the lion’s share of the market in their pocket, it isn’t surprising they’re also quite popular. A prime example of a FTSE 100 monopoly stock is National Grid (LSE:NG.) – the UK’s energy transmission infrastructure operator. It’s been one of the most popular UK stocks to own, and with a multi-decade-long history of consistently hiking dividends, the firm’s been a lucrative source of passive income. However, management’s been shaking things up, and dividends suffered a cut. What’s on the horizon for this business, and how much can investors earn in dividends under the new status quo? The fact that almost every British household and business is dependent on National Grid is why regulators allow the firm to exist as a monopoly. Yet it seems even monopolies can run into financial troubles when becoming overly dependent on debt. With interest rates sitting near 0% for over a decade, the firm used this cheap money to expand and improve. But with rates now aggressively higher in light of inflation, the group’s...