Initial public offering price was 210 pence per share, giving HSS a total market capitalisation of 拢325m.
The price is at the bottom end of the 210p to 265p range announced last month.
The offer will raise total gross proceeds of 拢103m for the company and 拢11m for the selling shareholders assuming no exercise of the over-allotment option, or 拢22m assuming exercise in full of the over-allotment option. The offer represents 35% of issued shares, if no over-allotment.
Chief executive Chris Davies said: "We are delighted to have completed the IPO process successfully and, with proceeds from the offer enabling us to accelerate our growth, we are excited about our future as a listed business.
"Our focus now will be on executing our proven strategy, and building on our established track record of industry-leading growth and returns on assets, for the benefit of all our shareholders."
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