Unions have hit out after two companies announced more than 300 job losses at their plants in Wales.
Visteon said it was winding down its brakes business
The Solectron electronics factory in Cwmcarn, near Newbridge is closing with 150 job losses, while 175 jobs are to go at the Visteon car plant at Swansea.
Unions called the proposed Solectron closure a "kick in the teeth."
The announcements came as the Burberry factory in Treorchy shut after 60 years and the Aeron valley cheese plant in Felinfach, Ceredigion, also closed.
Martin Rhisiart, from the Cardiff Business School, said the week had been "a microcosm of the business world".
"We've had job losses and job creation even in the same sectors," he said.
"At the beginning of the week we had the announcement in Llanelli of Connaught - the specialised hybrid sports car being built there - and at the end of the week we have this job announcement with Visteon in Swansea."
The factory is earmarked for closure in October 2007
Mr Rhisiart said the job gains and losses were simply movement in the "global supply chains" of industries.
He added: "It's inevitable sometimes we will be able to gain some jobs, but other times... we actually lose them."
Solectron, which makes telecommunications equipment, has now entered a 90-day consultation on the site's future.
The company blamed "changing market conditions" and said moving jobs to "lower-cost regions" was an option.
Grace Mitchell, from the Communication Workers Union, said the possible closure of the factory three years ago had been avoided, but since then the company had been cutting the workforce and transferring work overseas.
She said: "It is a fact of life these days that jobs are being moved abroad but I don't think it's a fact of life that we should all have to sit back and pay the price for them.
"In the case of our members, that's a very high and bitter price indeed."
And in Swansea, car components plant Visteon said 175 jobs would go as they wound down their brakes business.
The company blamed Ford's decision to close a foundry in Leamington Spa, Warwickshire, which the company supplies with parts.
Catherine Speight, regional secretary for Amicus, said: "Visteon have been telling us over the last 12 months that this is a business that they're wanting to exit, it's not seen as part of their core business any more.
She added: "Working with the people still left at Swansea and, with the management, we can make sure we try and protect as many of the jobs there so that another company would want to come and buy the plant."
The Burberry factory closed with the loss of more than 300 jobs
There were emotional scenes on Friday at the end of a long-running campaign to save the Burberry clothing factory in Treorchy, where the gates closed for the final time.
More than 300 people have been made redundant, despite a high-profile campaign which attracted support from celebrities, including Ioan Gruffudd and Tom Jones.
Meanwhile, the Aeron valley cheese plant also closed its doors in Ceredigion, ending 56 years of milk processing in the area.
Farmers' Union of Wales spokesman called it a "devastating blow".
He added: "The loss of 44 jobs in a community such as this is devastating, especially on top of the job losses last year following the closure of the adjacent Dairygold plant."
It followed the closure last year of the nearby Dairygold Factory, which resulted in 115 jobs being lost.