Here comes services PMI ...

Readings on the strength of the service sector are coming up on Tuesday morning.

Markit Economics is set to release its latest services PMI report at 9:45 am ET, with ISM expected to follow with its non-manufacturing report on business at 10:00 am ET.

Expectations are for both measures to show service sector activity continued to expand in January at a pace similar to the prior month.

Markit's reading it expected to come in at 54.1, up slightly from 53.3 in December, while ISM's report is expected to come in at a 56.4, just below 56.5 in December.

Any reading above 50 indicates expansion in the sector, while readings below 50 indicate contraction.

We'll be back with the live numbers when they hit.