One of the most daunting questions for a beginner is: "How much should I actually put into stocks versus bonds?" While there is no universal answer, financial professionals have developed several frameworks based on the most critical factor in your investment journey: Time. Your age and your "time horizon" (how long until you need the money) dictate how much risk you can afford to take.

The "Rule of Thumb" Models: Simple Math for Allocation

For decades, the standard starting point for asset allocation has been a simple subtraction formula. These rules are designed to automatically decrease your risk as you get older.

The "100 Minus Age" Rule

This classic rule suggests that you should hold a percentage of stocks equal to 100 minus your current age .

Example: If you are 30 years old, you would put 70% in stocks (100 - 30 = 70) and 30% in bonds .
Example: If you are 60 years old, you would put 40% in stocks (100 - 60 = 40) and 60% in bonds .

Modern Variations: 110 and 120

Because people are living longer and retirement can last 30 years or more, many advisors now suggest using 110 or 120 as the starting number . This keeps you invested in stocks longer to combat the long-term effects of inflation.

The 120 Rule for a 30-year-old: 120 - 30 = 90% stocks. This is a much more aggressive stance, acknowledging that a 30-year-old has decades to recover from market downturns .

Target-Date Funds: The "Set-It-and-Forget-It" Solution

If you find the "Rule of Thumb" too manual, Target-Date Funds (TDFs)—also known as lifecycle funds—do the work for you. These are mutual funds or ETFs designed to be a one-stop-shop for retirement . You simply choose the fund with the year closest to your expected retirement (e.g., "Target 2055").

The Glide Path Concept

The defining feature of a TDF is its glide path. This is the pre-determined schedule by which the fund manager automatically shifts the asset mix .

Early Years: When the target date is far away, the fund is aggressive, holding mostly stocks (often 90%+) to maximize growth .
Approaching the Date: As the year 2055 approaches, the fund gradually "glides" into a more conservative mix, selling stocks and buying bonds to preserve the wealth you've built .

Case Study: Vanguard Target Retirement 2030 (VTHRX)

As of mid-2025, this fund is designed for people retiring in about five years. Its allocation reflects that proximity:

Stocks: ~61% (for continued growth and inflation protection) .
Bonds: ~38% (for stability and income) .
Short-term Reserves: ~1% (for liquidity) .
The fund achieves this by holding four other broad index funds, covering the total U.S. and international stock and bond markets .

Comparison: Target-Date Funds vs. Index Funds

Feature	Target-Date Funds	Index Funds
Management	Active adjustment of the mix	Passive tracking of an index
Convenience	High; one fund does everything	Moderate; you must build the mix yourself
Fees	Generally higher (due to management)	Generally very low
Control	Low; the manager sets the glide path	High; you decide the exact allocation
Tax Efficiency	Lower (due to internal rebalancing)	Higher (lower turnover)

Retirement-Specific Strategies: Ladders and Annuities

As you move from the "accumulation" phase (saving) to the "distribution" phase (spending), your allocation model needs to prioritize dependable income.

The CD and Bond Ladder

Instead of buying one large bond or CD, you "ladder" them. You buy multiple instruments that mature at different intervals (e.g., 6 months, 12 months, 18 months, and 2 years) .

Benefit: When the 6-month CD matures, you have cash available. If you don't need it, you reinvest it at the current interest rate. This protects you from being "locked in" to a low rate if interest rates rise .

Annuities for "Guaranteed" Income

Annuities can act as a "personal pension." You give an insurance company a lump sum in exchange for a guaranteed monthly payout for life .

SPIA (Single Premium Immediate Annuity): Starts paying you immediately .
DIA (Deferred Income Annuity): You invest now, but the payments start at a future date you choose .
These are excellent for covering "essential" expenses (mortgage, food), allowing you to keep your remaining portfolio in stocks for "discretionary" spending (travel, hobbies) .

FAQ: Age and Allocation

Q: I'm 25. Should I have any bonds at all?
A: While the "100 minus age" rule says 25%, many young investors choose 0-10% in bonds to maximize growth, provided they can stomach the volatility .

Q: Are Target-Date Funds "safe"?
A: They are diversified, but they are not "guaranteed." If the stock market drops 30%, a TDF with a far-off date will also drop significantly .

Q: What if I want to retire early?
A: You should choose a TDF with a date closer to your actual goal, or manually adjust your "Rule of Thumb" to reflect your shorter time horizon.

Q: Why do TDFs have higher fees?
A: You are paying for the "fund of funds" structure and the professional management of the glide path. However, these fees have been trending down significantly in recent years .

By understanding where you are in your lifecycle, you can choose a model that provides the right balance of "gas" (stocks) and "brakes" (bonds). Whether you use a simple math formula or a sophisticated Target-Date Fund, the goal is the same: ensuring you don't have too much risk when you're old, and you don't have too little growth when you're young.