What if I had invested $100 a month in Sony
Investing a fixed amount every month, whatever the price: that is dollar-cost averaging. Here is what this strategy would have done in Sony, depending on the year you started.
Since December 2003, Sony (a stock listed in Tokyo and quoted in yen) returned only +6.1% a year in dollar terms, +285.2% over nearly 23 years. For a monthly investor, almost every purchase was made below today's price: 98% of the 275 monthly buys since December 2003.
Data: Yahoo Finance monthly closing prices, up to date as of (latest update November 5, 2026) MethodAuthor: Yann Avondo
If I had invested $100 every month in Sony since January 2016, today I would have $28,321
Over the same period
Worst moment: −48.9% between December 2021 and September 2022. To get this result, you had to hold on without selling.
Sony at a glance
Sony is now as much an entertainment group (PlayStation, film, music) as an electronics maker, and dominates smartphone camera sensors. Tracked here through its Tokyo listing, in yen.
Its worst fall, 83.1% in dollar terms between May 2007 and November 2012, was only erased in September 2018, 11 years and 4 months after the peak. Against the MSCI World, this calculator's yardstick (+7.0% a year in dollar terms over the same period), Sony roughly matched it. Its best calendar year was 2017 (+61.0%), its worst 2008 (−61.8%); in all, 18 up years out of 22.
$100 a month in Sony, by start year
One contribution at the start of each month since January of the given year, valued at the latest price. Click a year for the full story.
| Start | Invested | Worth today | Multiple | Annual IRR |
|---|---|---|---|---|
| $2,300 | $2,538 | ×1.1 | +10.2% | |
| $3,500 | $4,306 | ×1.23 | +14.3% | |
| $4,700 | $6,143 | ×1.31 | +13.7% | |
| $5,900 | $7,970 | ×1.35 | +12.2% | |
| $7,100 | $9,502 | ×1.34 | +9.7% | |
| $8,300 | $11,754 | ×1.42 | +9.9% | |
| $9,500 | $14,829 | ×1.56 | +11.0% | |
| $10,700 | $17,950 | ×1.68 | +11.3% | |
| $11,900 | $22,450 | ×1.89 | +12.3% | |
| $13,100 | $28,321 | ×2.16 | +13.4% | |
| $14,300 | $34,331 | ×2.4 | +13.8% | |
| $15,500 | $43,300 | ×2.79 | +14.8% | |
| $16,700 | $52,507 | ×3.14 | +15.2% | |
| $17,900 | $63,881 | ×3.57 | +15.6% | |
| $19,100 | $70,078 | ×3.67 | +14.8% | |
| $20,300 | $75,095 | ×3.7 | +14.0% | |
| $21,500 | $81,706 | ×3.8 | +13.4% | |
| $22,700 | $86,099 | ×3.79 | +12.6% | |
| $23,900 | $89,274 | ×3.74 | +11.8% | |
| $25,100 | $92,886 | ×3.7 | +11.2% | |
| $26,300 | $97,345 | ×3.7 | +10.6% | |
| $27,500 | $101,663 | ×3.7 | +10.1% |
Lump sum or DCA in Sony?
Since January 2016, investing in Sony all at once (lump sum) multiplied the stake by ×5.34, +16.6% a year. Investing every month (DCA) multiplied the total contributions by ×2.16, an annual return (IRR) of +13.4%.
Here the lump sum did better: money invested early rode the whole rise. That is the most common outcome on an asset that goes up.
Frequently asked questions
How much would I have if I had invested $100 a month in Sony for 10 years?
Investing $100 every month since January 2016, $13,100 in total, would be worth about $28,321 today: an annual return (IRR) of +13.4% (price only, in the displayed currency).
What if I had started investing $100 a month in Sony in 2015?
Since January 2015, $14,300 invested in total would be worth about $34,331 today (IRR of +13.8% a year).
What if I had started investing $100 a month in Sony in 2020?
Since January 2020, $8,300 invested in total would be worth about $11,754 today (IRR of +9.9% a year).
Is investing monthly better than investing all at once?
Historically, investing a lump sum right away returns more in most cases, because markets rise more often than they fall. But monthly investing smooths the purchase price, protects against the worst timing and matches how people actually save: from their paycheck, month after month.
How is the annual return calculated?
With spread-out contributions, the multiple of the amount invested does not tell the whole story: the last dollars had only a few months to grow. The IRR (internal rate of return) is the average annual return that, applied to each contribution from its date, produces the final value.
Compare with
Before you have regrets
What this calculation does not tell you.
Hindsight bias
Picking Nvidia or Bitcoin today means picking known winners. Back then, nothing set them apart from hundreds of assets that went nowhere or vanished.
Holding on was the real test
The result assumes you never sold, including through the drawdowns shown above. Very few investors actually do.
The broad market, no bet required
The MSCI World never makes headlines, but it does not require guessing the winner. It is the fairest yardstick for any pick.
Method: past performance, computed from split-adjusted monthly closing prices (intra-month lows are smoothed out). Converted at each month’s exchange rate; no fees, no taxes. The MSCI World benchmark is the price index, excluding dividends. Sources: Yahoo Finance (prices, exchange rates, US Treasury bills), Eurostat (inflation), published regulated rates (Livret A). Not investment advice. NokxiHub.