A dedicated squad of officers has been set up to track down the masked man, who is thought to quickly change his clothes after a heist in a bid to evade capture.
Police are now trying to enlist the help of city businesses to report any suspicious activity near their premises, particularly between 8pm and 10pm when the robber has repeatedly struck.
But officers have warned members of the public and shop staff not to approach the suspect, who is considered highly dangerous, and extra police patrols have now been launched in the city centre.
Only six gunpoint robberies were reported in the whole of Lothian and Borders during last year, and the suspect has already matched that figure single-handed since June 2.
Three off-licences in Dalry Road, Melville Drive and North West Circus Place have been targeted, along with a trio of bookmakers in Leith Walk, West Maitland Street and Lothian Road.
In each case, a robber pulled out a handgun and demanded cash and in at least one he was also armed with a meat cleaver.
Chief Inspector Kevin Murray, from the West End police station, said: “We are keeping our options open, but we are looking at whether the same person is responsible for these six crimes. There are similarities which run through each of these robberies.
“We believe this person will probably be hanging around to check a premises then changing clothes quickly to go inside and then probably changing again outside.”
Witness descriptions following each robbery have been similar, with the suspect described as being 5ft 6in to 6ft tall with an athletic build. The robber typically wears dark trousers and a dark jacket, as well as a scarf or Balaclava. Officers believe he has a good knowledge of the city centre area.
A team of 14 officers has been involved in investigating the robberies, with community officers and other specialists also taking part. Officers have visited 40 bookmakers in the city, as well as numerous off-licences and other shops to give staff advice on keeping safe.
Chief Insp Murray added: “A key priority for the force is crime prevention through engagement and our officers regularly visit residential and commercial properties to offer relevant advice and guidance.
“However, another excellent way for businesses to ensure they are not targeted is through communication with one another. Information sharing has already proven itself to be successful with Edinburgh’s pubs and clubs as part of the Unight scheme.
“We now hope that staff within the city’s other businesses will find similar success by passing on details of suspicious activity to their colleagues in neighbouring premises.”
Councillor Tom Buchanan, the city’s economic development leader, said: “I hope with the help of the business community and the wider public these crimes can be solved swiftly before anyone else becomes a victim. Anyone who is aware of any suspicious activity which may help the police should contact them immediately.”