Ryanair remains one of the more volatile and more interesting shares. The airline's share price was hit heavily during the recent market upheaval. Reports that British Airways was about to enter the low-cost airline market appear to have been responsible for the fall of nearly a quarter in the share price during the recent market turbulence, although it has recovered a little since.

How worried should Ryanair investors be about this prospect? Certainly it is already operating in very competitive markets. And the airline is bound to face tough competition as it tries to translate its success on the Dublin to British routes to other European routes. Fighting Aer Lingus and trying to get Aer Rianta to reduce airport charges is one thing. But trying to push into routes in Europe may generate a competitive response of an altogether different magnitude.

What of BA? In a research note this week, NCB says fears about BA's entry to the lowcost segment are exaggerated. Ryanair has a two-to-three-year lead over other low-cost airlines in Europe, NCB points out, and even BA is likely to start into this market in a modest way. BA will be wary of cannibalising its own routes, NCB says, and would face close regulatory scrutiny of its tactics.

Against this background, NCB remains bullish about Ryanair. This seems a fair view, but clearly much depends on the ingenuity and expertise of the airline's management and its ability to repeat the low-frills formula across Europe.