UK stocks were expected to open slightly higher on Wednesday after three straight days in positive territory.However, gains were likely to be limited ahead of a raft of economic data, including services purchasing managers' indices (PMIs) from the Eurozone and UK, Eurozone retail sales and US factory orders. City sources predict the FTSE 100 will open around 10 points higher than yesterday's close of 6,829.17.Stocks have risen in recent sessions as investors speculated that stimulus measures could possibly be announced by the European Central Bank (ECB) on Thursday following a recent spate of gloomy economic indicators."With all eyes on tomorrows ECB rate meeting and the weak manufacturing numbers earlier this week, markets will be hoping for better numbers from the services sector this morning," said analyst Michael Hewson from CMC Markets UK.Stocks to watchFinal results from Hargreaves Lansdown showed assets under administration were less than consensus expectations but the company was optimistic about its ability to deal with new regulatory changes. The FTSE 100 financial services group lifted total assets under administration up 29% at £46.9bn, versus forecasts of at least £48m, but delivered earnings per share of 34.5p, up 9% and in line with consensus estimates.Equipment rental group Ashtead is likely to move early on after saying it expects to beat full-year expectations as profits jumped by a third to a record high in its first quarter, helped by strong revenue growth and improving margins. Chief executive Geoff Drabble said that the company "continue[s] to capitalise on recovering markets" and that its US and UK divisions of Sunbelt and A-Plant took further market share during the period.Housebuilding and construction firm Galliford Try announced that it has been awarded two new affordable housing contracts worth a combined £106m. BC