# Monthly 60/40 Equilibrium
Source: https://www.yieldcurve.pro/blog/60-40-equilibrium-009  
Published: 2024-08-15  
Tags: 60/40, Bonds, ETFs, SPY, Stocks, TLT, noindex

_What do current market movements in stocks and bonds have to say about 60/40 fund weights?_

# What do current market movements in stocks and bonds have to say about 60/40 fund weights?

<br />

This is the August 2024 installment of a
<a href="/blog/60-40-equilibrium-001">series</a>
of posts we make to track how the weights of a synthetic 60/40 stock/bond
portfolio evolve intra-month.

Each month we coduct a simple experiment:  track the cumulative intra-month
return of two stock/bond indices (say SPY and TLT).  Next, combine that data to
estimate a one standard deviation envelope of weights as a function of the days
in the month.  Then measure where the current weights sit within the envelope.
This provides a measure of how much a typical 60/40 fund needs to move in order
to restore equilibrium.

Figure 1 depicts the envelopes and current weights for SPY and TLT.

<br />

<img src="/admin/blog/image/78/blog_60_40_equilibrium_009.png">
#### **Figure 1**: Stock/Bond Weights For July 2024

<br />

On an absolute basis, stocks have under performed bonds by about 450 basis points
(just eyeballing the above charts).  Let's take a look at the stock-bond weightings
month-to-date on a relative 60-40 basis.

Stocks are about 125 basis points below average (the thick grey line) at this
point in the month based on historical data.  Based on symmetry this means that
bonds are about 125 basis points below average.  Assuming these positions are
maintained until the end of the month, this means that 60/40 funds will be net
buyers of stocks and sellers of bonds in order to restore equilibrium.

See you next month.

Cheers -- YCP