The ASX 200's best-performing stocks in 2026 - are any still a Buy?

EOFY is a great time for companies and investors alike to take stock and even take profits. 

But it's also a good opportunity to assess what's been happening more broadly in markets. One way to get a quick sense of what's been working is to analyse the best-performing stocks, which often serve as a great indicator of where the areas of opportunity have been. 

Here, I'm taking a look at the top four performers of the ASX in the first half of 2026 and whether they could still represent an opportunity in the second half of the year. We'll focus only on companies in the ASX 300 to exclude speculative or penny stocks. 

Given how the AI trade has continued to dominate markets in 2026, it's no surprise to see this list dominated by AI-adjacent names, but more than one is still rated at least a Buy by brokers, suggesting there could be more upside for investors heading into FY27.

1.  Megaport Ltd (ASX: MP1)

• Year-to-date return: 81.97%
• Current price: $21.40
• Consensus rating: Strong Buy (7 Buys, 1 Hold, 0 Sells)
• Upside potential: 5.48%

After jumping a staggering 320% since its April low, Megaport now tops the list of best-performing ASX stocks this year.

Earlier this month, the company announced it was looking to raise almost $830 million to build out its own AI inference service, i.e. when a user employs an AI model to perform a task. It has also signed four new AI contracts worth $459 million. 

The network-as-a-service provider connects data centres across the world via virtual ports that businesses can access and is well positioned to succeed in the AI compute sector.

Despite its recent run, broker consensus still suggests modest upside potential, with some brokers targeting a higher share price. 

JPMorgan recently raised its price target to $28 following the latest announcements, citing material earnings upgrades and a compounding IRR opportunity (>20%) given its potential as a global AI inference provider. 

Macquarie are similarly targeting a share price of $27.80, arguing the AI compute venture removes two of the major reservations over holding MP1 - earnings volatility and a muddled strategy. The announcements now show "predictable growth & clear 2Y payback on Contract capex", according to Macquarie.

"MP1 is a quality counterparty relative to other players in market and has much smaller order sizes than Hyperscale-only players."

Its probable inclusion in the ASX 100 in the medium term is also seen as a catalyst, given the significance of passive flows.

2. Weebit Nano Ltd (ASX: WBT)

• Year-to-date return: 71.74%
• Current price: $8.69
• Consensus rating: N/A
• Upside potential: N/A

Another AI winner, Israel-based Weebit Nano is a semiconductor company specialising in memory technology via its ReRAM product. 

Like Megaport, and many other global semiconductor and memory names like SK Hynix and Sandisk, it has skyrocketed from its April low of $3.49 and now sits at $8.71 a share.

It upgraded its FY26 revenue guidance to $12 million, but net losses grew to $30 million in 1H26 as a result of significant R&D spending. It has also secured a partnership with Texas Instruments and a $102 million in an institutional capital raise, but remains years away from profitability.

It is looking to transition to a commercial, licence-based business and has successfully completed two customer product tape-outs, another name for the final phase of the semiconductor design process in which the blueprint is locked in and sent away for manufacturing. 

Weebit Nano is also not covered by major brokers and therefore has no consensus ratings or price targets. 

3. Sims Ltd (ASX: SGM)

• Year-to-date return: 62.3%
• Current price: $29.20
• Consensus rating: Buy (5 Buys, 4 Holds, 0 Sells)
• Upside potential: 5.04%

Metals recycler Sims has been another beneficiary of the ongoing AI buildout, with its Sims Lifecycle Services (SLS) business driving earnings alongside better-than-expected performance in its traditional metals business. 

Since mid-2024, it has almost tripled in price, but has surged in 2026 as memory chip resales accounted for 80% of gross profit. 

Broker ratings suggest there is still some modest upside potential for SGM, given the robust performance of its metals business. 

UBS says US steel demand metrics show we may be in the middle of a cyclical recovery - with key scrap prices up ~15% in the last 6 months - as a catalyst for more earnings. 

"With ongoing US reshoring and industrialisation supporting domestic steel production, we see this as a sustained tailwind for scrap demand and prices, driving further potential upside for the Metals business." 

Macquarie increased its price target to $34.40, citing upgraded FY26 EBIT guidance and scrap metal price momentum as drivers. But there remains earnings uncertainty over decommissioning timing and how the SLS economics may shift over time. 

Sims was also Yarra Capital Management's Marcus Ryan's pick for a stock that could kick on in FY27 in last week's Buy Hold Sell, targeting a share price above $35 thanks to the strength of its SLS business. 

4. Codan Limited (ASX: CDA)

• Year-to-date return: 49.1%
• Current price: $42.42
• Consensus rating: Buy (4 Buys, 2 Holds, 0 Sells)
• Upside potential: 5.65%

Codan's dual businesses of metal detection devices and tactical communications have enjoyed strong years off the back of two of 2026's key themes: surging precious metal prices and a global uptick in defence spending. 

CDA has rocketed more than 1,000% since 2023, and is up 47% in 2026 after huge earnings upgrades across both its core divisions. FY26 net profit is forecast to exceed $170 million,  with revenue expected to grow beyond FY27. 

It also recently announced the acquisition of Adaptive Dynamics, a US engineering company specialising in anti-jamming and interference mitigation technology.

Goldman Sachs said Codan's integration track record suggests it should be able to execute and expand its acquisitions, especially in its communications business. Moelis Australia suggested Adaptive Dynamics had also demonstrated it could drive US defence funding and commercialisation, against a favourable macro backdrop for the defence sector. 

Macquarie argued that Codan's opportunity in defence should continue to grow, noting "recent conflicts in Ukraine and the Middle East have underscored that the future of warfare is increasingly reliant on UxV systems. Lessons from Ukraine are accelerating a global shift towards resilient, military-grade solutions."

"Additional tailwinds include the push for sovereign capability, ecosystem expansion and platform integration, and a rapidly evolving technology roadmap."

What have been your best performers in 2026?

Have you backed a stock that's beaten the best performers on the ASX this year? Let us know in the comments below.