Yeah, the US is an outlier. In most countries the government doesn't back mortgage loans so we have to refinance after a few years. Basically every mortgage in countries like Canada and the UK is what the US would consider an "ARM".
Probably the end of a fixed interest period approaching. This is the case for some %age of the total number of mortgages out there every year. It's also the moment you're going to be taken advantage of.
Taken advantage of because you have to deal with them. Previously you had the option to walk away. But when the fixed interest term expires you are going to have to make some kind of deal because very few people can switch to being homeless or paying off their entire mortgage at the drop of a hat.
Presumably a 10/30 loan or something similar. Many homeowners are facing the same problem with the interest rate now being significantly higher than when they got a 10/30 initially.