ARM price seems to be going through a three month flattish period after a 1 year or so steady rise. Any views on what might happen next?

Well, HARRYCAT, it's Yes - and - No from me. . . . We, that's "UK-Them" allowed our business to fail . . . motorcycles that were only for Real Men, as m/c's spent most of the time in bits.... whereas the Competition just worked - and offered Electric Start . . . which appealed to the non-Treehuggers ( and women?).
Cars - that were targeted by lazy workers and Unions that perpetuated practices that were hugely dragging the profitability. Add-in the Press having the idea that every New Model is an opportunity for jokey headlines ( -And this applied to All industries, bless 'em.).....not helped by those in charge having little understanding of Engineering (( Still the case in Parliament - where a basic O-level/GCSE should be the minimum in Maths, Biology, Physics and Mechanics, IMHO.)).
Nuclear was destroyed by the Lobbyists believing that Nuclear meant making Bombs - not helped by some "Told you so..." plant explosions in Japan, USA and Russia.
So now we are "forced" to buy Nuclear Plants from CHINA . . . and France . . . .Just as we buy Pedelino Trains from Italy ( Our invention that Gov. was unable to see was indeed the future to upgrade existing track in the short-term ).
Steel has suffered from World prices -

The problem for non-Nationalised business is the Shares are Openly traded for the benefit of the short-term . . . . not as a LT business that will continue to provide profits for many years to come - together with UK-employment.
e.g Look at the Solar-Power industry ( madness IMHO, until Conversion is ~3x present levels ) . . . yet we are being encouraged to buy . . . providing jobs for Foreign manufacturers ( of the wafers ) . . . .

Look to the areas in the UK where "old industries" have been lost - and tell me what ANY Government has done to provide employment on the scale to recover Regional economies. So-called investment schemes are too-soon withdrawn - as there is no strategic plan, based on a LT need.... for the products.

Did I hear we ( after BrExit ), are going to invest in xxxxx and yyyyy - Or was that a Re-run of well-worn Political posturing. . . ? ( Yes it was! ).