Five men have been convicted of kidnap, robbery and firearms charges following the £53m raid at a Securitas depot in Tonbridge, Kent, in 2006.
Two other men were cleared of all charges by the jury, following a trial lasting seven months.
The five who were convicted are due to be sentenced on Tuesday.
During the raid the depot manager, Colin Dixon, his wife and their child were kidnapped at gunpoint by men posing as police officers.
The family was told: "You will die if you do not do as you are told," the Old Bailey heard.
Those found guilty are: Stuart Royle, 49, of Allen Street, Maidstone, Kent; Jetmir Bucpapa, 26, of Hadlow Road, Tonbridge; garage owner Roger Coutts, 30, of The Green, Welling, south-east London; Lea Rusha, 35, of Lambersart Close, Southborough, Kent; Emir Hysenaj, aged 28, of New Road, Crowborough, East Sussex.
They had all denied conspiracy to kidnap, conspiracy to rob and conspiracy to possess firearms.
The judge warned that the guilty men faced "very substantial" sentences.
John Fowler, 59, of Chart Hill Road, Staplehurst, Kent, and Keith Borer, 54, of Hempstead Lane, Maidstone, Kent, were cleared of involvement in the robbery.
The gang wore prosthetic disguises, normally used by actors, which were made by hairdresser Michelle Hogg.
She was initially charged by police but agreed to become a prosecution witness when all charges against her were dropped.
Speaking after the jury returned its verdicts, Roger Coe-Salazar, the chief crown prosecutor for Kent, said: "When you have a case of this magnitude it's easy for it to be romanticised like Ocean's 12 as a victimless crime.
"There is nothing romantic about a child being held at gunpoint by a masked man. This was a callous and highly dangerous crime."
CCTV cameras captured armed robbers holding the Dixon family and 14 members of staff hostage as they loaded cash into the back of a 7.5-tonne lorry.
Since the robbery in February 2006, police have recovered £21m of the stolen cash, the court was told.
Rusha, Royle, Coutts and Bucpapa were among robbers who burst into the Securitas depot in the early hours of 22 February 2006.
Rusha was one of the two men dressed as police officers who first kidnapped Mr Dixon then his family at gunpoint.
Hysenaj was a Securitas employee who filmed inside the depot using a hi-tech video camera the size of a 50p coin that was fitted to his belt.
Investigators were stunned by the scale and audacity of the biggest ever cash robbery in Britain.
The gang got away with what was described as a "king's ransom" in cash, but left behind £153m because no more could be fitted into their lorry.
Prosecutor Sir John Nutting told jurors that the robbers were inspired by the lure of "luxury, ease and idleness" and were prepared to target the "innocent and vulnerable" to achieve it.
After being kidnapped, the Dixon family was driven to the Securitas depot and tied up along with 14 terrified workers.
CCTV footage taken from the depot showed the robbers were armed with a Skorpion machine pistol, a pump-action shotgun, a handgun and an AK47 assault rifle.
Money gone abroad
Cash storage cages were used to imprison the hostages, who were warned as the robbers fled in the lorry: "We know where you live."
The Dixons' child eventually wriggled through bars in the cages and helped free the others.
Police said there was evidence of the robbery being planned as far back as July 2005, but the gang made mistakes which helped lead the 100-strong team of officers to them.
A large quantity of the missing money is thought to be in northern Cyprus and Morocco, in cash and assets.
A bin bag containing £105,600 was found buried under a tree at car dealer Mr Fowler's property, Elderden Farm in Kent.
He told police the location of the money while the farm was being searched, saying he found the money in a vehicle which had been returned to him.
Kent Police confirmed in court that the investigation into the raid cost in excess of £5m and was unprecedented in its scale.