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the stop-loss order book provides vital information to
inform agents’ ability to trigger cascade events, par-
ticularly to maximise their return.
4.3 Position Closing
We have shown that the direction in which an agent at-
tempts to cause a price cascade affects the price move-
ment within the market and hence the profit an agent
may obtain. Given the size of the agent’s position it is
also vitally important, both for the agent and for the
market as a whole, to study how the agent closes their
position.
We experiment with 3 strategies that the agent
may use to close their position. We examine how this
affects the agent’s profit, as well as observe how this
alters the price path observed within the market.
1. Buy and hold: An agent holds and receives a
“marked to market” value of their shares at the
conclusion of the simulation period. (Assume the
agent closes their position without slippage.)
2. Single Trade Closure: An agent waits a set pe-
riod t then fully closes their position. This ensures
the agent’s closing share balance is equal to their
opening balance.
In our implementation the agent conducts a single
order, 1, 000 ticks after their initial large order.
3. Spread Trade Closure: An agent makes multiple
(n) trades, to close out their position and return to
their initial share balance over time t.
In our implementation, the agent conducts 10
trades of equal size over the proceeding 10,000
ticks after their initial large order.
Each of the strategies was tested with both an up-
ward (buy) and downward (sell) shock. Both con-
ditions were tested with 50 simulations for 100, 000
ticks on the date of 11/21/2021. Figure 4, and Figure
3 (b) and (d) display the visual impact these strate-
gies. While Table 3 shows the profit generated by
each strategy, and Table 4 displays the market volatil-
ity for each experimental set-up.
We once again observe a difference in shock
size between the buy/sell experiments. We therefore
highlight the importance of the shock direction on the
size of the cascade. This is shown both visually in
Figure 4 and numerically by the increase in volatility
noted in Table 4. Together this suggests that the
structure, and likely the skew of the stop-loss order
book largely contributes to the size of the cascade
and that the existence of support/resistance has the
potential to mute the effect of the shock. Therefore
we hypothesise that knowledge of stop-loss order
sizes and locations could be a key determinant in the
success of such shock agents.
When considering the profitability of the agent we
see that both the direction of the agent’s trade and the
closing strategy employed significantly alter its out-
come. If an agent may only utilise a buy and hold
strategy it is most advantageous to create a downward
shock ($2,210, 000 vs. −$2,530,000), and in fact the
agent loses money if it initiates an upward movement.
However, when undertaking either of the other strate-
gies (single trade closure or spread trade closure) it
is more profitable for the agent to cause an upward
price movement ($2, 060, 000 & $2, 140,000 for up-
ward shocks compared to, $98, 100 & $525,000 for
downward shocks). This dichotomy highlights both
that the closing strategy of the agent, and also that
structure of the stop-loss book are vitally important
in informing the agent’s decision if it seeks to gain a
profit. By examining Figure 3(b) it is possible to see
why this effect may occur. When the agent undertakes
the strategy of buy and hold it forces the price in a di-
rection, however, if the agent waits too long to close
it’s trade, it allows time for the price path to progress
and gives other agents within the simulation more of
chance to influence the price progression. However, if
the agent fully closes their trade within a smaller pe-
riod of time, it is able to take advantage of the power
it exerted over the market. This is illustrated by the
single trade closure and spread trade closure strate-
gies. In both cases, the agent closes its trade in a
timely fashion after exerting control over the market.
Although, in the case of the single trade closure the
agent causes a ”whiplash” effect within the market.
Spiking the price almost as far in the opposite direc-
tion from its original trade, and diminishing the profit
the agent generated. Whereas the spread trade clo-
sure strategy allows the agent sufficient time to min-
imise this whiplash effect, whilst also enabling it to
close its position within a reasonable time allowing it
to benefit from its previous price altering efforts.
Given this propensity to create whiplash effects
within the market, it is interesting to examine the ef-
fects of these strategies on the volatility of the market
as a whole. Table 4 describes the volatility of each
scenario. Interestingly we see that when we compare
the buy and hold closing strategy with spread trade
closure strategy the level of volatility is very simi-
lar (within ∼ 2%). Meanwhile, the single trade clo-
sure strategy results in overall volatility that is ∼ 25%
larger than buy and hold. This, once again emphasises
the impact of the closure strategy, while also indicat-
ing that the triggering of stop-loss orders has a part
to play in this. The single trade method is likely to
reactivate newly placed stop-loss orders.
The Role of Stop-Loss Orders in Market Efficiency and Stability: An Agent-Based Study
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