Two Scalable Growth Plays: Interactive Brokers and Micron Technology

For the growth investor, the goal is not just to buy a profitable company, but to buy a company with the infrastructure to dominate a large market. This means focusing on two core concepts: scalability and Total Addressable Market, or TAM.

Scalability is the ability to grow revenue without a proportional rise in costs. In a scalable model, the incremental cost of serving one more customer is minimal. This is the hallmark of businesses built on technology, automation, or digital infrastructure. As one analysis notes, scalable companies operate in a way that allows them to serve more customers and increase profits along the way, while non-scalable models often see costs rise just as quickly as revenue, capping their potential scalability refers to a company's ability to grow revenue without a corresponding rise in costs. The classic example is a software-as-a-service platform, where adding a millionth user costs almost nothing beyond server capacity. This efficiency fuels long-term business success and can deliver life-changing returns.

TAM defines the theoretical ceiling. It is the estimated total revenue potential within a specific market if a company captured 100% of it the total addressable market (TAM) reflects the revenue that a company could theoretically generate, assuming a 100% market share. It's a measure of the opportunity, not a guarantee. For a growth stock, a large TAM is essential because it signals that even a small percentage of market share can translate into massive revenue growth over time.

Viewed through this lens, the investment thesis shifts. Current profitability is secondary to future dominance. The focus becomes on market penetration and technological leadership. A company with a scalable model can aggressively capture market share without destroying margins, turning a large TAM into tangible revenue. Evidence supports this view: the online broker Interactive Brokers, with its low-cost, highly automated operation, has aggressively taken market share from competitors, driving strong revenue growth the company's stock even outperformed Nvidia last year as it aggressively took market share from competitors. Its business model is built for scale, allowing it to expand internationally and serve more markets efficiently. The growth investor sees such a company not as a current earnings story, but as a vehicle to capture a significant portion of a vast market.

Interactive Brokers: Scaling a Low-Cost Brokerage Model

Interactive Brokers is executing a textbook playbook for a growth investor: capturing a large, expanding market with a scalable, low-cost model. The company's extreme automation is its core advantage, enabling a streamlined operation that fuels aggressive market share gains the company's culture of automation overflows into every area of its business. This isn't just a cost-cutting measure; it's a strategic lever for scaling efficiently across more than 170 global markets and serving clients from over 200 countries

. At Interactive Brokers, clients from more than 200 countries and territories can invest in over 170 global markets.

The results are a direct function of this scalable model. Customer accounts grew 32% year over year to 4.13 million in Q3 2025, a pace that has continued into the new year with total client accounts reaching about 4.4 million in December 2025. This rapid customer acquisition is the engine for asset growth, which is the true driver of revenue. Client equity surged 40% year over year to $357.5 billion in the third quarter. This explosion in assets directly fuels the company's two primary revenue streams: net interest income and trading commissions.

The model's efficiency is clear. Even as the company adds millions of new accounts and hundreds of billions in assets, its financials show strong leverage. Revenue grew 21% year-over-year to $1.655 billion in Q3, while earnings per share jumped 40% revenue of $1.655 billion in Q3 2025, up 21% year over year... earnings per share rose 40% to $0.59. This demonstrates that the incremental cost of serving this new customer base is low, a hallmark of scalability. The company's ability to maintain high engagement, with daily average revenue trades up 34% year-over-year, shows these new assets are active and profitable DARTs... increased 34% year over year to $3.62 million.

The bottom line is a powerful growth flywheel. A large TAM for online brokerage provides the runway, and Interactive Brokers' automated, low-cost model is built to capture it efficiently. The evidence shows the company is not just growing; it is scaling its asset base at a faster rate than its customer count, indicating that each new account is bringing significant capital. For a growth investor, this is the ideal setup: a company with a proven, scalable infrastructure rapidly expanding its footprint within a massive market.

Micron Technology: Capturing the AI Memory Boom

The AI memory market is the ultimate growth story, and Micron Technology is positioned at its epicenter. The company's Total Addressable Market is defined by the insatiable demand for high-bandwidth-memory (HBM) chips, the specialized memory used in AI processors. This demand is so intense that Micron is already sold out of its HBM chips through 2026, a clear signal of a market in structural shortage Micron is already sold out of AI memory chips through 2026. This sold-out backlog is not a temporary spike but a reflection of a multi-year infrastructure build-out, providing a high-visibility revenue runway.

Micron's scalability is being proven through aggressive, capital-intensive expansion. The company is moving beyond incremental capacity increases to a strategic build-out of its manufacturing footprint. This includes starting construction on a massive new chip fabrication facility in New York and signing a deal to purchase a fabrication facility from Powerchip Semiconductor Manufacturing Corporation started construction on its massive chip fabrication facility in New York... signed a deal to purchase a fabrication facility from Powerchip Semiconductor Manufacturing Corporation. These moves demonstrate a commitment to scale production at the pace of demand, a critical factor for a cyclical industry where supply constraints can quickly erode pricing power.

The translation of this demand and capacity push into explosive financial growth is already evident. For its fiscal third quarter, which ended in November, Micron's revenue is projected to be between $8.6 billion and $9 billion For 3Q FY2025, its revenue is projected to be between US$8.6 billion to US$9 billion. This follows a period of staggering growth, with revenue for the full fiscal year ending last August surging to $37.38 billion from $25.11 billion the prior year. The company's ability to ramp production and capture this demand surge is the hallmark of a scalable model in action. Even with only about 60% of the current demand being met, the path to sustained high growth is clear.

The bottom line is that Micron is executing a classic growth investor play. It has identified a massive, secular TAM in AI memory, secured a leading position in that market, and is now scaling its manufacturing capacity to meet it. The sold-out backlog provides near-term visibility, while the aggressive expansion plans aim to capture even more of the soaring market. For investors, the question is not if the AI memory boom will happen, but whether Micron can scale fast enough to own a dominant share of it. The evidence suggests it is building the infrastructure to do just that.

Practical Investment Insight: Catalysts and Risks

For investors, the growth story is only half the equation. The other half is understanding the catalysts that will drive the next leg up and the risks that could derail it. Here's a clear-eyed look at what to watch for each company.

For Interactive Brokers, the primary catalyst is straightforward: continued market share gains and the resulting client equity growth. The company's scalable, automated model is built to convert its rapid customer acquisition into a larger asset base. Evidence shows this flywheel is working, with client equity surging 40% year-over-year to $357.5 billion last quarter client equity surged 40% year over year to $357.5 billion in the third quarter. The key watchpoint is the pace of that asset growth relative to customer count. If the company can maintain or accelerate its asset growth rate, it confirms the model is scaling efficiently. The main risk is a market downturn. As a brokerage, Interactive Brokers' revenue is directly tied to client assets and trading activity. A significant market correction could compress client equity and trading volumes, pressuring net interest income and commission revenue. Investors should monitor the company's customer growth metrics and daily average revenue trades for signs of resilience or strain.

Micron's catalyst is execution. The company is sold out of its high-demand HBM chips through 2026, creating a high-visibility revenue runway Micron is already sold out of AI memory chips through 2026. The critical next step is scaling production to meet that sold-out backlog. The company's aggressive moves to build new fabrication capacity in New York and acquire facilities are the tangible proof of this commitment. The primary risk is a potential peak in the AI memory cycle. While demand is soaring now, the semiconductor industry is inherently cyclical. If AI infrastructure spending slows or competitors ramp up supply faster than expected, pricing power could erode, threatening the explosive growth trajectory. The key watchpoint is quarterly revenue guidance. Micron's guidance for its fiscal third quarter, projected between $8.6 billion and $9 billion, will be a crucial data point on whether the sold-out backlog is being converted into actual sales at the expected pace For 3Q FY2025, its revenue is projected to be between US$8.6 billion to US$9 billion.

In short, for Interactive Brokers, watch the asset growth engine; for Micron, watch the execution of its capacity expansion. Both companies are in strong positions, but the growth narrative depends on these near-term catalysts overcoming their respective risks.