What to Invest In

A stock is a share of ownership in a company. When you own one, your fortunes rise and fall with that business, so stocks are the higher-risk, higher-return part of most portfolios. Over long periods they have historically delivered the strongest average returns of the mainstream asset classes, but with the largest swings along the way.

• Higher potential return. Most of the return comes from the price rising as the company grows; some companies also pay dividends.
• Higher risk. Prices can fall sharply, and an individual company can drop a long way or fail entirely.
• How people hold them. You can buy individual shares or, more commonly, own hundreds at once through a fund. For a walkthrough of the mechanics, see how to invest in stocks.

A bond is a loan. When you buy one you lend money to a government or company for a set period, and in return they pay you interest on a schedule and return your principal at maturity. Because it is a contractual loan rather than ownership, a bond is steadier than a stock and mostly about income and preserving capital, at the cost of a lower long-run return.

Bonds are not perfectly safe: their prices move when interest rates change, and a borrower can default, so higher yields usually signal higher risk. But as a group, high-quality bonds are the calmer counterweight to stocks. For a fuller side-by-side, see stocks vs bonds.

An ETF (exchange-traded fund) and an index fund are both ways to own many securities through a single purchase. An index fund tracks a market index; it can be structured as a mutual fund or as an ETF. An ETF trades on an exchange like a stock throughout the day, while a traditional index mutual fund prices once daily. The appeal of both is instant diversification, usually at very low cost.

• Broad-market funds track a wide index such as the S&P 500 or the total US market. Common examples include VOO and VTI.
• Sector and theme funds hold a slice of the market, like technology or semiconductors.
• Bond and dividend funds package income-focused holdings, such as SCHD for dividend stocks.

For the different fund structures and what beginners often start with, see our overviews of the types of funds and the best ETFs for beginners.

Real estate is a tangible asset that can produce rental income and appreciate over time. Buying property directly takes significant capital and effort, so many investors get exposure through REITs (real estate investment trusts): companies that own income-producing property and whose shares trade like stocks. REITs are known for paying out most of their income as dividends and for behaving somewhat differently from stocks and bonds, which makes them a common diversifier.

Real estate still carries risk. Property values fluctuate, and REIT share prices can swing and are sensitive to interest rates. It is an option to diversify and add income, not a guaranteed steady performer.

Cash equivalents are low-risk, easily accessible places to hold money you cannot afford to see fall. They prioritize safety and access over growth, so returns are modest but your balance stays steady.

• High-yield savings accounts pay interest while keeping your money available.
• Money market funds hold very short-term, high-quality debt.
• Certificates of deposit (CDs) lock money in for a set term at a fixed rate.
• Treasury bills are short-term government debt considered very low risk.

These are where an emergency fund and money you need within a year or two often sit. For a broader look at steadier options, see low-risk investments.

The table below summarizes the general character of each asset type. These describe broad tendencies, not rules for any single security or fund.

In short: stocks for growth, bonds for income and stability, ETFs and index funds for low-cost diversification, real estate and REITs as a diversifier, and cash equivalents for safety and near-term needs. Most portfolios use a blend rather than a single type.

Deciding what to invest in is less about picking a “best” asset and more about matching the mix to your situation. Three questions do most of the work:

• Your goal. What is the money for? A retirement decades away and a house down payment in two years call for very different choices.
• Your time horizon. A longer horizon can generally support more in stocks, because there is more time to recover from downturns. Money you need soon usually leans toward bonds and cash.
• Your risk tolerance. How large a drop can you sit through without selling? A more stock-heavy mix aims for growth and bigger swings; a bond- and cash-heavier mix aims for stability.

Once you have a sense of these, the next step is an asset mix (how much in stocks versus bonds and cash), then the specific funds or securities to fill it. Ready-made mixes by risk level are laid out in our asset allocation models guide, and combining holdings so no single one dominates is covered in how to build a diversified portfolio. These are general frameworks, not personal advice.

Walnut is a tool for seeing your investing picture clearly, not a source of instructions. It can show how your current holdings are split across asset types, let you build a thematic basket and track how it would have moved against a benchmark, and place trades you approve yourself at your own broker. You connect any major US broker, chat through Claude, ChatGPT, or built-in AI, and stay in control of every decision. It is read-only by default, and Walnut does not tell you what to buy.