Dollar-Cost Averaging With a Little Timing Built In
Watching the red days
Dollar cost averaging has one basic job: take the guesswork out of buying. Pick an amount, pick a schedule, and buy that amount on that schedule no matter what the market’s doing that day. It works because it keeps you from trying to call tops and bottoms, which nobody does reliably over time. But there’s a variation on the theme I’ve been using for years in my own portfolio, and it came up recently in conversation with my son about dollar cost averaging into Bitcoin, LEAPS, and a few ETF positions. It’s a small adjustment, but over a long enough runway it adds up to something real.
Standard dollar cost averaging says: same amount, same interval, regardless of price. Buy $100 of something every month, rain or shine. There’s nothing wrong with that. The variation I use keeps the same dollar amount and the same general cadence, but adds one condition — I wait for the stock to be down before I buy.
Here’s where this comes from directly. I run something I call the Lunar Landing Portfolio, and whenever a new stock gets added to that list, I open a position with a small stake — a few dollars, often less than a full share. Just enough to establish a foothold. From there I build the position over time using this down-day method. Right now I’m holding around 32 positions in that portfolio, most of them modest in size, and individually they’re volatile — swings of 2 to 4 percent in a single day are routine, sometimes more. They don’t all move together, so on any given day some names are up and some are down.
That’s the whole mechanism. I check the portfolio around midday. Whatever’s down 3 percent or more that day gets a small buy — I take my daily allotment, split it across however many names are down (sometimes one, sometimes six, sometimes ten), and buy into those specifically. Whatever’s up, I trim a little, which frees up cash for the next down day. It’s not really “timing the market” in the classic sense — I’m not trying to guess where the bottom is. I’m just extending the purchase window from a single fixed moment to a few days of watching, and buying on the day within that window when the price happens to be lower.
If you’re not checking daily, the same logic scales down easily. Say you get paid monthly and set aside $100 to $200 for buying in. Instead of buying on the same calendar date no matter what, watch your positions for a 3-to-5-day window around payday. Most of the time, somewhere in that window there’s a red day. That’s the day you buy. When it’s time to trim something for cash, do the reverse — wait for a green day.
Two things this depends on. First, it only makes sense in a tax-advantaged account — an IRA, a 401(k), a Roth. Once trades trigger capital gains taxes or you’re paying commissions, this kind of frequent in-and-out trading stops making sense. I do all of this inside an IRA, where trades cost nothing and the tax consequences aren’t triggered by moving in and out of positions. Second, it only works on stocks that trend upward over time — ideally ones that outpace the broader market. If you’re dollar cost averaging into something that’s just going down, none of this helps; you’re catching a falling knife, not buying a dip in an uptrend. The idea is to overweight your buys toward down days in names you already believe belong in the portfolio for the long haul.
Does it always work out better than the plain version? No. Sometimes a stock climbs three days straight and then dips on day four, and in hindsight buying on day one would’ve been just as good or better. You don’t get it right every time. But averaged across many small decisions over years, this tilt toward buying red and trimming green has given me something like a 1 to 2 percent edge over just buying on autopilot at a fixed interval, regardless of price.
A 1 to 2 percent edge sounds small in any given year, and it is. But compounding doesn’t care about small — it cares about consistent. If the NASDAQ averages something like 13 percent a year over the long run, and this approach nudges your effective return to 14 or 15 percent, that gap compounds hard over 10, 15, 20 years. You don’t need to beat the index with stock selection to benefit from this. Even just applying it to something as plain as QQQ — buying more on the days it’s down, trimming on the days it’s up, within your normal contribution schedule — gets you the same lift.
So the actual instruction is small: know you’re buying this month, watch for the down day, buy then. Know you’re trimming, watch for the up day, trim then. That’s the entire technique. It’s not dramatic, and it won’t feel like much in the moment. But stretched out over decades of compounding, that couple of percentage points is the difference between a good retirement account and a great one.
This reflects one investor’s personal approach and is shared for informational purposes, not as financial advice. Tax treatment and suitability depend on your own accounts and circumstances — consult a qualified financial or tax professional before adopting any investment strategy.