Fractional Shares and Micro-Investing in Australia: How They Work

This guide breaks down what fractional shares and micro-investing actually are, which Australian platforms offer each, the ownership trade-offs involved, and how you can start investing with small amounts — including on US shares, where Selfwealth now supports fractional trading from as little as US$1.

This article is general information only — see the full disclaimer at the end before making any investment decisions.

What are fractional shares?

A fractional share is exactly what it sounds like: less than one whole share of a company or ETF. Instead of needing the full share price upfront, you invest a dollar amount and receive a proportional slice.

For example, if a share is trading at $1,000 and you invest $100, you'd own 0.1 of a share.

Fractional shares are common in the US market, where firms like Charles Schwab and platforms with US access make dollar-based investing straightforward. Selfwealth's US trading now runs on Alpaca's brokerage infrastructure, which supports fractional trading — so Australians can buy fractional US shares through Selfwealth from as little as US$1, alongside whole-share investing on the ASX.

*Being rolled out gradually across the Selfwealth customer base — if you can't see this feature in your account yet, it's on its way rather than unavailable.

In Australia more broadly, fractional access is still limited and tends to apply to specific markets rather than a whole portfolio — it's worth checking exactly which markets a platform's fractional feature covers before assuming it applies everywhere.

What is micro-investing?

Micro-investing is the broader idea: building an investment portfolio with small, regular amounts of money rather than one large lump sum. It's less a specific product and more a way of investing.

Common micro-investing mechanics in Australia include:

• Round-ups — spare change from everyday purchases is invested automatically

• Small recurring deposits — e.g. $20 a week into a portfolio or ETF

• Low minimum investments — some apps let you start from as little as $5

Fractional shares are one tool that supports micro-investing (they let a small dollar amount buy part of an expensive stock). But plenty of Australian micro-investing apps — Raiz, Spaceship Voyager and CommSec Pocket among them — work by buying units in diversified ETFs or managed portfolios rather than fractional slices of individual companies. So you can micro-invest without ever touching a fractional share, and you can buy fractional shares without following a "micro-investing" round-up model.

Which Australian platforms offer fractional shares?

Availability changes over time, so always confirm current features directly with a provider before signing up. As at the time of writing, based on publicly available information:

Selfwealth's fractional offering is currently US-only: on the ASX side, holdings remain whole shares recorded against your own Holder Identification Number (HIN) under CHESS sponsorship, which is what gives you direct legal ownership rather than a pooled or custodial arrangement. On US shares, trading now runs through Alpaca's brokerage infrastructure, which supports fractional orders from as little as US$1 — useful if you want a small dollar amount of a higher-priced US stock without needing the full share price. We think it's worth being clear about which model applies to which market rather than blurring the two together — see the ownership section below for why it matters.

*Fractional US trading via Alpaca is being rolled out gradually to Selfwealth customers rather than available to all accounts at once.

The trade-off: how your shares are actually held

This is the part most comparison guides skip over, and it matters more than the minimum investment amount.

CHESS-sponsored whole shares

When you buy an ASX-listed share through a CHESS-sponsored broker, the trade is settled and recorded against your own HIN in the ASX's official share registry. You are the legal owner of record — there's no custodian sitting between you and the company whose shares you hold. You can see your holding independently of the broker, and if the broker ever ran into trouble, your shares are still registered in your name.

Custodial or pooled fractional holdings

Fractional shares can't be CHESS-sponsored in the traditional whole-share sense, because a fraction of a share isn't a discrete, transferable unit on the ASX registry — and the same principle applies to fractional US shares, which sit outside CHESS entirely. Providers get around this by holding the underlying whole shares themselves (often through a custodian or nominee structure) and recording your fractional entitlement internally. For example, Selfwealth's US fractional trades are executed and held via Alpaca's brokerage infrastructure rather than under a HIN. You still have an economic interest — dividends, price movements — but your legal position depends on the platform's custodial arrangement rather than direct registration in your own name.

Neither structure is inherently unsafe, and reputable AFSL-licensed providers operate both models. But it's a genuine difference worth understanding, particularly if direct ownership and being able to view your holding independently in the share registry matters to you.

Starting small: fractional US shares, or whole-share investing with Auto-Invest?

You now have more than one genuine option, depending on what you're trying to achieve.

Fractional US shares from US$1. If you specifically want exposure to a higher-priced US stock — think Amazon, Berkshire Hathaway or similar — without needing the full share price, Selfwealth's US trading now supports fractional orders from as little as US$1, powered by Alpaca's brokerage infrastructure. This sits alongside standard whole-share trading on the ASX.

Whole-share investing with a flat, predictable fee. For ASX shares and ETFs, Selfwealth charges a flat $9.50 brokerage per trade, regardless of trade size — so you know the cost upfront rather than paying a percentage that scales with how much you invest. Holdings remain CHESS-sponsored and registered directly in your name.

Regular, automated investing on top of either. Rather than manually placing every trade, Selfwealth's Auto-Invest feature lets you set a recurring order — weekly, fortnightly or monthly — into a chosen stock or ETF, so you're dollar-cost averaging into the market without needing to time individual trades. If you're new to the mechanics of buying your first stock, our step-by-step guide walks through the basics, and our ETF guide covers diversified options that suit smaller, regular contributions particularly well.

Which combination makes sense depends on what you're investing in and how much you value direct ASX ownership versus flexible access to expensive US stocks. Dollar-cost averaging doesn't guarantee better returns than investing a lump sum, and neither approach removes market risk — you're still exposed to prices falling as well as rising. What both offer is a way to build a position gradually without needing a large amount of capital upfront.

Pros and cons of fractional shares

Potential advantages:

• Access to expensive stocks with a small dollar amount — for example, US shares from as little as US$1 via Selfwealth's Alpaca-powered US trading

• Easier to build a diversified spread across many companies with limited capital

• Can support automated, hands-off investing strategies

Things to weigh up:

• Often held via a custodial/pooled structure rather than in your own name

• Selection may be limited to certain markets or a subset of listed stocks

• Selling a fractional position can be less straightforward than a whole share, depending on the platform

• Tax reporting (e.g. capital gains) on fractional holdings can be more complex — a registered tax agent or ASIC's Moneysmart can help clarify your specific situation

Pros and cons of micro-investing apps generally

Potential advantages:

• Very low entry point — some apps start from $5

• Automation (round-ups, recurring deposits) helps build a savings habit

• Good for learning the basics before committing larger amounts

Things to weigh up:

• Management or subscription fees on small balances can eat into returns proportionally more than on larger balances

• Many micro-investing apps limit you to pre-set ETF portfolios rather than individual stock choice

• As with all investing, capital is at risk and past performance is not a reliable indicator of future returns

How to choose between fractional shares, micro-investing apps, and whole-share investing

This comes down to what you're optimising for, and it's worth thinking through rather than defaulting to whichever app is easiest to open:

• Want direct legal ownership of ASX shares, plus the flexibility to buy expensive US stocks in smaller dollar amounts? A platform that offers CHESS-sponsored whole shares on the ASX and fractional access on US markets — such as Selfwealth — covers both without needing separate accounts.

• Want to invest specifically in one very expensive US stock with a small amount and don't mind a custodial structure? Any fractional-share platform, including Selfwealth's US fractional trading, can suit that specific goal.

• Want the simplest possible "set and forget" experience with pre-built portfolios? A dedicated micro-investing/round-up app may be the easiest starting point, with the trade-off of less control over individual holdings.

None of these is universally "better" — it depends on your goals, how hands-on you want to be, and how much you value direct ownership versus convenience. This article can't tell you which is right for your circumstances; a licensed financial adviser can help with that if you'd like personalised guidance.

If this sounds like the right fit, you can sign up to Selfwealth to trade whole ASX shares, fractional US shares from US$1, and set up Auto-Invest from within the app.

FAQs

Are fractional shares available on the ASX? 

Fractional trading is limited on the ASX because CHESS-sponsored holdings are recorded as whole shares under your own HIN. A small number of providers offer fractional access to certain ASX shares through custodial arrangements rather than traditional CHESS sponsorship. Selfwealth's fractional offering currently applies to US shares rather than the ASX — availability varies by platform and changes over time, so check directly with any provider you're considering.

Is micro-investing worth it for beginners? 

It can be a low-pressure way to build a habit of investing regularly, especially while you're learning. As with any investing, returns aren't guaranteed and your balance can go down as well as up — it's worth comparing fees relative to your likely balance size before committing.

Do you pay tax on fractional shares in Australia? 

Generally yes — the same capital gains and income tax principles that apply to whole shares apply to fractional holdings, though record-keeping can be more complex. This is general information only; speak with a registered tax agent or see ASIC's Moneysmart for guidance relevant to your situation.

What's the difference between CHESS-sponsored and custodial share ownership? 

CHESS-sponsored means your ASX shares are registered directly in your name under your own HIN — you're the legal owner of record. Custodial (or "issuer-sponsored"/nominee) structures mean a third party holds the shares on your behalf, and you hold a beneficial interest rather than direct legal title.

Can I start investing with just $50 in Australia? 

Yes — via micro-investing apps with low minimums, some fractional-share platforms, or by choosing a lower-priced ETF or share and investing regularly through a flat-fee broker. The right approach depends on whether you prioritise low minimums, direct ownership, or automation.

Does Selfwealth offer fractional shares? 

Yes, on US shares — Selfwealth's US trading is powered by Alpaca's brokerage infrastructure, which supports fractional orders from as little as US$1. ASX shares remain whole-share, CHESS-sponsored trades. Brokerage is a flat $9.50 per trade, and Auto-Invest is available for scheduled, recurring investing.

What's the minimum amount to buy a fractional US share with Selfwealth? 

US$1 is the minimum buy for fractional US stock trades through Selfwealth. Standard brokerage and any applicable FX conversion costs still apply, so it's worth checking the current fee schedule before trading small amounts, as fees can take up a larger share of a very small trade.