Electro Optic Systems Holdings Ltd (ASX: EOS) shareholders have an unusual opportunity sitting in front of them.
But it is only available to certain investors, and the deadline is coming up fast.
At the time of writing, the EOS share price is down 7.40% to $11.02.
Even after the fall, the ASX defence stock is still trading well above the $8 price attached to its current share purchase plan (SPP).
That means eligible shareholders could buy new EOS shares at a major discount to the current market price.
Based on the current share price, the gap between $8 and $11.02 is about 38%.
Of course, that gap could change quickly if the share price moves before the new shares begin trading.
So, what's going on here?

Image source: Getty Images
A discounted offer for existing shareholders
EOS opened its SPP on 25 May.
Under the plan, eligible shareholders can apply for up to $30,000 worth of new shares at $8 each.
The offer is only available to shareholders who were on the register at 7pm AEST on Friday, 15 May 2026.
The offer is due to close at 5pm AEST on Tuesday, 9 June 2026.
EOS expects to announce the results of the SPP on Friday, 12 June, with new shares due to be issued on Tuesday, 16 June.
Those shares are expected to begin trading on Wednesday, 17 June.
Why the discount looks so large
The $8 offer price was set as part of a much larger capital raising.
EOS recently completed a $150 million institutional placement at the same price.
It also announced a $40 million strategic placement to Generation 5 Holding L.L.C, a related entity of Abu Dhabi-based defence group Calidus L.L.C, alongside another defence-focused institutional investor.
EOS said the institutional placement price represented a 9.3% discount to the last traded price before the raising was announced.
But the share price has moved strongly since then. EOS shares touched an all-time high of $12.58 on Tuesday, before some investors took profit.
That has left the SPP price sitting well below where EOS shares are currently trading.
The company said proceeds from the capital raising will help fund the upfront consideration for the MARSS acquisition.
Management said it will also use the funds to strengthen the balance sheet, alongside its secured term loan facility from Washington H. Soul Pattinson and Company Ltd (ASX: SOL).
EOS completed the MARSS acquisition on 21 May.
MARSS is a Europe-based provider of AI-enabled command-and-control systems for counter-drone capability.
The return is not guaranteed
Keep in mind, this isn't a guaranteed 38% return.
The share price could fall before the new shares begin trading.
EOS also has the right to scale back applications if demand for the SPP is higher than expected.
The company is targeting up to $25 million through the SPP, though it can accept more or scale back applications at its discretion.
That means eligible investors may not receive the full number of shares they apply for.
There is also the wider question of valuation.
EOS shares have already had a huge run over the past year, helped by rising interest in remote weapon systems (RWS) and high-energy laser weapons (HELW).
The discounted SPP may look attractive on paper, but investors still need to weigh that against the risks of buying after such a strong rally.