In a letter to clients, Gibbs said one of the company's trading platforms was still operational in allowing customers to open and close positions.
"However, there will be a delay in deposit/withdrawal functionality until we have clearer information."
One investor who wished to remain anonymous said he had about $102,000 invested through Halifax, which acted as a conduit for Interactive Brokers, an Australian-based securities firm with capital of $6 billion.
He said he has taken steps to try and de-link his portfolio from Halifax so he has a direct relationship with Interactive Brokers instead.
"I'm pretty gutted, obviously," he said. "But there may be a path for some people, myself included. I'm not even sure; I've just filled in the forms and prayed."
The investor said he wasn't what he'd describe as "a big fish" - having initially started with $7000 and putting in about $67,000 over two or three years.
"I'm just a Joe Blogs guy trying to get enough money for a deposit on a house."
Another investor said he also had $100,000 tied up with Halifax and knew of several "builder mates" who between them had a further $400,000.
He said he had heard nothing from the company.
"It's a very big shock. We are one group but there are many others."
Another Auckland investor who gave his name as Luke said he was also frustrated by the lack of information.
"I was told I can't withdraw my money. Only the administrator has access to the funds, and I can't say if my investment is safe or not," he told the Herald.
He said he didn't know how many people are affected but he knows a couple of friends who have funds with Halifax.
Halifax NZ offers margin foreign exchange, CFDs, shares and options trading. It is regulated by the Financial Markets Authority.
A statement posted on the Ferrier Hodgson website said the administrators of Halifax Investment Services are assessing the best course of action and focusing on the best outcome for investors.
"The investors are our primary concern at the time," administrator Morgan Kelly said.
"We are conducting an urgent investigation into the business operations and will ensure all stakeholders, creditors, investors and employees, are updated of any developments."
A creditors' meeting will be held in Sydney on 5 December 2018.
Most recent accounts filed to the Companies Office reveal Halifax NZ earned brokerage and subscription revenue of $2.4m in the year to March 31 for a profit of $16,726.
The company is required to maintain net tangible assets of at least $1m or 10% of revenue.
In June 2015 it obtained a $1.2m subordinated loan from its Australian parent top meet the requirement. The terms provide Halifax Investment Services with security over the assets of the company.
At the March 31, 2018 balance date the balance of the loan was $1.11m.
Halifax NZ gained a derivatives issuer license from the FMA in June 2015 allowing it to transact a variety of financial instruments including futures, options, forex and CFDs.
The company also can transact shares on local and international share markets.
It has offices in Auckland and Wellington.
