Apple reports its fourth quarter results when the markets close in the US later today (8pm Irish time) and all eyes will be on the number of iPhones sold over the past three months.

Over the last three quarters, the iPhone has delivered up to 70% of all Apple revenues.

The consensus forecast is for 49m handsets, representing a 25% jump over the same period last year.

The really crucial quarter for Apple though, is the current three months ending at Christmas, which will actually constitute first quarter 2016.During that period last year, the company sold a quarterly record of 74.5m phones

Meanwhile, Twitter is due to report third quarter results.

Newly-returned Chief Executive Jack Dorsey recently told the market revenues would come in more than 50% higher than the same period last year at $560m and the number of Twitter users would rise by a relatively modest 7 million.

The revenue boost will be welcome news for investors, as the company has found it notoriously difficult to monetise its userbase of over 300 million active users.