Up 106% in December, this stock has one of the biggest Santa Claus rallies on the ASX

If you’ve been watching the ASX this December, Electro Optic Systems (ASX: EOS) has been hard to miss.

EOS shareholders could hardly ask for a better Christmas present given that the defence technology company’s share price has surged 106% in December alone, and is now up an eye-watering 617% year to date. Its a year to date return that eclipses fellow defence tech company Droneshield (ASX: DRO) (up 336% year to date).

So what’s driving one of the strongest Santa Claus rallies on the market?

2025: a breakout year for EOS

2025 has been a big renaissance year for EOS after it began the year with a share price almost 90% below its all time high.

Since then however, the company has been steadily announcing new customer contracts across its product portfolio, and this has sent its share price sky-rocketing higher.

The latest leg higher came yesterday (23 December), when EOS shares jumped 7.8% after the company revealed that it had secured a binding $33 million contract to supply its Remote Weapon Systems (RWS) to General Dynamics Land Systems, one of the largest defence manufacturers in the world.

As part of the contract, EOS’ Remote Weapon Systems will be integrated onto a major U.S. Army ground combat platform, with work delivered over the next two to three years. Manufacturing will take place at EOS’ facility in Huntsville, Alabama, further cementing its presence in the US defence market.

For investors, this matters because EOS has long talked about cracking the US market. This deal represents a genuine entry and expansion point in that market, and management has flagged that it could lead to larger follow-on orders (although nothing is guaranteed).

A month stacked with good news

This wasn’t a one-off announcement either, December has been a busy month for EOS.

Just days earlier, EOS had announced a $32m RWS order for another North American customer, with production scheduled for 2026– 2027.

Mid-month, the company also unveiled a conditional $120m contract for a high-energy laser weapon system with a customer in South Korea.

Add it all together, and EOS’ unconditional contract backlog now exceeds $400m, up from just $136m a year ago. Most of that revenue is expected to start landing in 2026 and beyond.

Foolish bottom line

Defence spending is rising globally, and EOS sits in some of the most attractive niches including remote weapon systems, counter-drone technology, and laser weapons.

After years of promise, EOS is now backing up its story with real contracts from serious customers. That’s why the market has rewarded the stock so aggressively this Christmas.

With strong momentum to end the year, EOS investors are repricing higher a business that’s firing on all cylinders.

The post Up 106% in December, this stock has one of the biggest Santa Claus rallies on the ASX appeared first on The Motley Fool Australia.

More reading

• Up 83% in a month, is it too late to buy DroneShield shares now?
• Here are the top 10 ASX 200 shares today
• Why EOS shares are jumping on Tuesday
• My 5 top stocks to buy in 2026
• Buy, hold, sell: DroneShield, Macquarie, and Wesfarmers shares

Motley Fool contributor Kevin Gandiya has no positions in any of the stocks mentioned. The Motley Fool Australia’s parent company Motley Fool Holdings Inc. has positions in and has recommended DroneShield and Electro Optic Systems. The Motley Fool Australia has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.