"Bitcoin could not make a clear counter-trend last week and gold is on a run at the moment with 7 per cent gains since its December lows," Marburger told the Standard.
Speculators are seeking safety from the "crazy volatility" of the cryptocurrency, according to Marburger.
"Gold has a sustainable track record over decades and is an asset you actually hold in your hands. People are looking for something to touch rather than an investment where only the belief in it is the value," he said.
"Bitcoin has proven one time more than it is based on speculation."
Marburger told the Times how he sold 30kg of gold worth around £1 million ($1.9m) on January 16.
Wall Street veteran Peter Boockvar has added to investors' concerns, warning of an impending "epic crash" which could slash 90 per cent off bitcoin, according to The Sun.
Boockvar told CNBC the cryptocurrency's value could fall to between US$1,000 and US$3,000 over the next year.
It's this uncertainty that is driving bitcoin owners to invest in the more reliable gold, according to Marburger.
Investors are believed to mostly be exchanging their bitcoins for sovereign coins of gold Britannia. One ounce is worth around £1,000.
Other gold merchants, including Goldcore, are also reporting similar trends.
Goldcore founder Mark O'Byrne told The Sun: "They [the bitcoin sellers] told us they were concerned that the massive price appreciation was unsustainable and they got nervous about it."
But not everyone is predicting doom and gloom for bitcoin's future, with some experts maintaining that the cryptocurrency will stabilise in the longer term.
Benjamin Dives, CEO of London Block Exchange, which plans to launch a direct sterling-to-bitcoin exchange, told the Standard that bitcoin's volatile week was not a cause for concern.
"[Some investors] may not be comfortable with the markets moving [downwards] and so are 'cashing out' to invest in traditionally stable assets, such as gold," he said.
"These people are likely new to cryptocurrency exposure or, as is standard in the investment industry, were just ensuring profits in the short term. The result for cryptocurrencies is a dip in the market, which is natural and healthy."
"As the market matures, we can be sure of more stability in the future and that is when these investors will be looking for a re-entry point. Unfortunately for them, their transition to gold may cause them to miss out on the gold rush."
