Betterment already manages rebalancing and tax optimization at scale—however there’s one other layer of worth working behind the scenes: execution. This paper focuses on how Betterment improves commerce execution by means of clever design and infrastructure. Our system doesn’t simply serve one section of customers; it applies equally throughout the platform, enabling everybody to faucet into scalable advantages that had been as soon as reserved for establishments. One key side is our use of marketable restrict orders—orders positioned close to or barely higher than the present market value to allow them to execute instantly. The sort of order is designed to strike a stability between velocity and value management: it seeks a quick execution whereas inserting a guardrail on how far the worth can drift. For shoppers, this implies better safety during times of market volatility—serving to be certain that trades don’t fill at costs considerably worse than anticipated.
One other foundational ingredient is our use of an omnibus buying and selling construction. Fairly than executing every particular person order individually, Betterment aggregates shopper trades permitting us to batch and route them extra effectively. This methodology helps us entry deeper liquidity and doubtlessly cut back total execution prices.
Via options like scheduled commerce home windows, omnibus aggregation, and a design that favors round-lot execution, Betterment helps reduce structural buying and selling disadvantages, cut back publicity to opposed choice, and improve the potential for improved pricing. These execution advantages compound with scale and are embedded immediately into the buying and selling expertise. The result’s better equity, effectivity, and cost-effectiveness for each investor on the platform.
The problem in retail execution
Retail buying and selling has developed considerably lately, fueled by technological innovation and elevated market accessibility. Nevertheless, key structural disadvantages persist for particular person buyers, particularly in the case of small, odd-lot orders and fast execution methods. Betterment’s managed execution framework—aggregating and scheduling trades all through the day—provides a strong and scalable various designed to scale back prices, mitigate execution threat, and higher align with the realities of market construction. Whereas trades are scheduled into structured home windows, they’re executed a number of instances in the course of the buying and selling day to stability timeliness with the chance for aggregations. Betterment doesn’t web opposing orders; every commerce is routed externally to our clearing associate.
Market construction and the significance of spherical tons
In fairness markets, commerce measurement performs a important position in figuring out execution high quality. A spherical lot—presently outlined as 100 shares for almost all of tickers—is the usual unit acknowledged by exchanges and market makers. These trades are included within the Nationwide Finest Bid and Supply (NBBO), prioritized in routing choices, and eligible for execution in institutional venues. Even mixed-lot orders that embody not less than one spherical lot (e.g., 105 shares) profit from this visibility, typically enhancing pricing for your entire commerce. In distinction, odd tons—any order smaller than a spherical lot—are excluded from the NBBO and sometimes expertise decrease precedence, lowered transparency, and worse pricing. These orders dominate retail investor flows and sometimes lead to much less favorable execution.
Authorized scholar Robert P. Bartlett III analyzed greater than 3 billion U.S. fairness trades in his 2021 paper and located that odd-lot orders acquired roughly 10% much less value enchancment than spherical tons. This is because of lowered visibility, exclusion from public quotes, and decrease precedence by execution venues. Trades of 99 shares had been notably deprived in comparison with trades of 100, even when each had been positioned concurrently. Excessive-volume shares like Amazon (AMZN) illustrated this disparity clearly—Bartlett estimated that over 30% of odd-lot trades in AMZN may have acquired higher pricing if executed as spherical tons.
Betterment’s managed buying and selling method is designed to assist mitigate these penalties by systematically aggregating shopper flows to succeed in round-lot thresholds, growing the probability of extra favorable outcomes.
Quantifying the affect: value discrepancies between lot sizes
A core function of Betterment’s execution technique is aggregating shopper orders to cross the round-lot threshold wherever doable. This isn’t only a choice; it’s a response to well-documented execution disadvantages that odd-lot orders face.
As an example what that form of pricing distinction may imply in greenback phrases, contemplate VTI, a extremely liquid safety steadily traded by Betterment shoppers. We chosen VTI as a result of it shares traits with AMZN—each are closely traded by retail buyers, profit from excessive liquidity, and are broadly in style. As of Could 2025, VTI trades at roughly $280 per share. If an odd-lot commerce receives even simply 2 foundation factors worse pricing than a spherical lot, this interprets to a price penalty of roughly $0.14 per share for odd-lot executions.
- For a 15-share odd-lot commerce: this implies a $2.10 greater value.
- For somebody investing $5k/month, this implies roughly $30 a yr in greater prices. Over a 30-year interval, this might equate to greater than $3,400 in missed positive factors, assuming 8% yearly progress.
The pricing examples introduced on this paper are primarily based on internally derived simulations that mirror market habits in step with the cited peer-reviewed analysis. These examples are meant for illustrative functions solely, are usually not meant to speak potential efficiency of any funding technique, and are usually not predictive of execution outcomes for any particular person commerce.
This pricing inefficiency compounds rapidly and has important implications when managing shopper belongings at scale. Betterment’s execution engine is designed to assist cut back this value by structurally creating alternatives to mixture orders into spherical tons. In keeping with our regulatory obligations, we purpose to realize finest execution—a regulatory customary that requires searching for probably the most favorable phrases moderately out there beneath prevailing market situations. This contains evaluating components reminiscent of value, velocity, probability of execution and settlement, and total value.
Betterment doesn’t delay trades to kind spherical tons, but it surely makes use of a system of time-based commerce home windows and an omnibus aggregation technique to opportunistically cross the round-lot threshold when shopper order stream naturally aligns. This permits us to systematically entry the extra favorable pricing situations sometimes related to round-lot trades—doubtlessly lowering value and enhancing execution outcomes for shoppers.
Whereas our mannequin is designed to enhance execution high quality within the mixture, particular person commerce outcomes could differ relying on market volatility, order measurement, and venue-specific components.
Commerce home windows as a mechanism for higher execution
Most retail brokers execute trades constantly, instantly passing orders to the market. Whereas this seems quick and clear, it exposes shoppers to dangerous microstructure dynamics. Excessive-frequency merchants (HFTs), for instance, exploit real-time alerts to seize unfold worth, typically on the expense of slower retail flows.
Betterment mitigates this by batching trades into scheduled commerce home windows. These home windows function all through the day and performance equally to frequent name auctions—an idea studied by Budish, Cramton, and Shim (2015). Their analysis exhibits that batched execution reduces the arms race in buying and selling latency, promotes equity, and narrows spreads. Although Betterment doesn’t run formal batch auctions, our home windows are meant to serve the same function: lowering predictability, concealing intent, and enhancing common execution.
This design additionally lowers market affect by consolidating demand. Liquidity suppliers can see bigger, extra common flows as an alternative of a loud, fragmented stream. A single bigger order is extra prone to appeal to aggressive pricing as a result of it alerts significant curiosity and is less complicated for liquidity suppliers to match towards present provide. For instance, a number of shoppers shopping for SPY over the identical commerce window are mixed into one order, lowering slippage—the distinction between the anticipated value and the precise execution value—and enhancing fills, or the probability that your entire order can be accomplished promptly at a fascinating value.
Execution in observe: Betterment’s technique
At Betterment, trades are executed in home windows all through the day. Every window consolidates related trades—purchase or promote, identical ticker—right into a single order, executed by means of an omnibus construction. Trades are routed by means of Apex, our clearing and buying and selling associate, to venues providing a aggressive mixture of value, liquidity, and fill reliability, with round-lot alternatives prioritized. We work to realize finest execution in all trades routed by means of this course of.
This construction introduces flexibility with out sacrificing equity. Betterment doesn’t delay execution for the sake of making a spherical lot, however we design the system to permit aggregation when sensible. If immediacy is critical—reminiscent of at day-end—we’ll execute no matter tons can be found.1 We additionally monitor managed accounts for rebalancing and tax-loss harvesting (TLH) alternatives. When Betterment’s buying and selling algorithm evaluates shopper accounts for tax loss harvesting and rebalancing alternatives, it usually prioritizes figuring out potential tax loss harvests forward of potential rebalancing alternatives. This exercise additionally performs a significant position in how we try to optimize outcomes alongside our execution practices. When shoppers’ orders align, aggregation and scheduling improve the probability of a positive end result.
1Betterment reserves the best to delay buying and selling beneath sure circumstances; extra details about our buying and selling practices and insurance policies is accessible in our Type ADV.
To assist oversight of Betterment’s execution high quality, Betterment has established a proper Finest Execution Committee tasked with oversight of execution high quality. This committee performs a daily and rigorous evaluation of buying and selling outcomes, assessing execution high quality throughout market facilities utilizing key metrics reminiscent of foundation level deviation from market value at placement (placement strike), routing habits, peer comparisons, and arrival value evaluation. Evaluations are made throughout ticker, order measurement, and timeframes.
Aggregation in motion: a comparative situation
To additional illustrate how aggregation results in higher execution, contemplate this instance the place three shoppers submit small trades across the identical time. When routed individually, these odd-lot orders are uncovered to the identical disadvantages outlined earlier—reminiscent of worse pricing resulting from exclusion from the NBBO. However when aggregated right into a single round-lot commerce, the order positive factors visibility and precedence, growing the probability of receiving higher pricing.
|
Consumer Orders |
With out Aggregation |
With Aggregation |
|
Alice: Purchase 35 shares |
Executed at $135.02 = $4,725.70 |
100 shares executed at $135.00 = $13,500.00 |
|
Bob: Purchase 40 shares |
Executed at $135.01 = $5,400.40 |
|
|
Carol: Purchase 25 shares |
Executed at $135.03 = $3,375.75 |
|
|
Whole Price Affect |
Whole: $13,501.85 (assorted, greater costs) |
Whole: $13,500.00 (uniform, higher pricing) |
Illustrative functions solely. Costs proven don’t mirror precise shopper execution outcomes.
This instance reinforces the sooner level about execution high quality variations between odd-lot and round-lot trades—such because the estimated 2 foundation level drawback present in high-volume shares like VTI. A consolidated 100-share order, just like the one proven right here, is extra prone to appeal to aggressive pricing from liquidity suppliers as a result of it’s simpler to match towards present provide and alerts significant demand.
This instance illustrates a core perception: retail buyers are deprived when fragmented. However once they act collectively—by way of an automatic platform like Betterment—they acquire entry to efficiencies usually reserved for giant institutional merchants.
Delivering institutional advantages to retail buyers
Betterment’s mannequin is designed to translate institutional market benefits right into a retail context. Institutional desks execute trades strategically—splitting orders, timing placements, and ready for liquidity. These strategies aren’t normally out there to people, however Betterment’s platform replicates lots of them algorithmically.
By aggregating trades to succeed in spherical tons, utilizing structured time-based execution, and accessing liquidity intelligently, Betterment prospects could profit from pricing and execution high quality much like what’s sometimes related to institutional requirements. This parity is particularly highly effective in unstable or illiquid situations, the place fragmented execution might be pricey.
Conclusion and client-centric outcomes
Managed buying and selling, as carried out by Betterment, is a deliberate, research-driven technique to beat the inherent flaws in retail execution. We mix commerce scheduling, order aggregation, and a impartial charge construction to ship significant benefits to particular person buyers. Our mannequin doesn’t assure higher execution on each commerce, however within the mixture, it enhances pricing, reduces slippage, and ranges the taking part in area.
Betterment believes that balancing immediacy and alternative is essential. Betterment could wait to mixture trades to hunt improved execution, which we imagine is a rational tradeoff. Betterment shoppers are usually not sacrificing management—they’re gaining effectivity. Over time, this technique is designed to create small however constant enhancements in return, aligning with our core mission: serving to shoppers benefit from their cash.
References
- Bartlett, R. P. III. (2021). Modernizing Odd Lot Buying and selling. Columbia Enterprise Regulation Assessment.
- Budish, E., Cramton, P., & Shim, J. (2015). The Excessive-Frequency Buying and selling Arms Race: Frequent Batch Auctions as a Market Design Response. Quarterly Journal of Economics.
- American Financial Affiliation. Analysis and publications on fairness market construction and buying and selling practices.
- NYU Stern Faculty of Enterprise. School analysis on market microstructure and equity.
- Australian Centre for Monetary Analysis (ACFR). Market design and fairness construction research.

